Microbiological and physicochemical changes of naturally black olives fermented at different temperatures and NaCl levels in the brines

The effect of different temperatures (25°C, 18°C and ambient temperature) and NaCl levels in brines (4%, 6% and 8%) on the microbiological and physicochemical characteristics of naturally black olives of Conservolea variety was studied for up to 190 days. Fermentation was carried out according to the traditional anaerobic method. The initial microflora consisted of Gram-negative bacteria, lactic acid bacteria and yeasts. Inhibition of Gram-negative bacteria was evident in all fermentations. The prevailing micro-organisms were lactic acid bacteria and yeasts, the association of which was dependent on the conditions of fermentation. At 25°C and 18°C in brines containing 4% and 6% NaCl, the growth of lactic acid bacteria was favoured resulting in a lactic acid fermentation, as indicated by the high free acidity levels and low pH values in the brines. On the contrary, 8% NaCl concentration affected the growth of lactic acid bacteria and enhanced the activity of fermentative yeasts, producing a final product with lower free acidity and higher pH value. At ambient temperature, the counts of lactic acid bacteria followed the fluctuation of temperature regardless of salt concentration, while yeasts did not seem to be affected. The lactic acid bacteria identified belonged to the species Lactobacillus mesenteroides, Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus pentosus. The best conditions for fermentation were at 25°C and 6% NaCl, developing free acidity of 142 mM (1·28% w/v) lactic acid and pH value of 3·8. After 5 months of brining, olives fermented at 25°C were judged by panelists as being debittered and ready to eat. No off-odour development was detected in any case due to anomalous fermentation. The HPLC analysis revealed that citric, malic, tartaric, succinic, lactic and acetic were among the end products of fermentation.     

Antimicrobial activity of weak acids in liquid feed fermentations, and its effects on yeasts and lactic acid bacteria

BACKGROUND: The efficacy of weak organic acids in the control of yeasts in pig liquid feed was studied taking into account the effects on lactic acid bacteria (LAB) responsible for beneficial fermentation. RESULTS: The yeast population in pig liquid feed was taxonomically identified. Kazachstania exigua, Debaryomyces hansenii and Pichia deserticola dominated the fermentation in liquid feed and whey. Pichia deserticola was found in whey and foaming liquid feed and dominated the fermentation after incubation. The sensitivity of the isolates against weak acids was measured in culture medium as well as in fermented and non‐fermented liquid feed. Formic acid and potassium sorbate successfully reduced the growth of yeasts in all media without interfering with LAB development. Both of these organic acids showed an increased antifungal effect when used in liquid feed fermented by a Lactobacillus plantarum strain. CONCLUSION: The loss of energy, reduced palatability and other practical problems due to the high growth of yeasts in fermented liquid diets can be reduced by organic acids without affecting lactic acid fermentation. Copyright © 2011 Society of Chemical Industry     

Evaluating the individual effects of temperature and salt on table olive related microorganisms

Statistical modelling techniques were used in the present study to assess the individual effects of temperature and NaCl concentration on the growth of 10 lactic acid bacteria and 6 yeast strains mostly isolated from different forms of table olive processing and belonging to the species Lactobacillus pentosus, Lactobacillus plantarum, Saccharomyces cerevisiae, Wickerhamomyces anomalus and Candida boidinii. The mathematical models obtained in synthetic laboratory media show that yeasts, except for C. boidinii, were more resistant to a high salt concentration than lactic acid bacteria, with an MIC value ranging from 163.5 (S. cerevisiae) to 166.9 g/L (W. anomalus); while for L. pentosus and L. plantarum this parameter ranged from 110.6 to 117.6 g/L, respectively. With regards to temperature, lactic acid bacteria showed a slight trend towards supporting higher temperature values than yeasts, with the exception of S. cerevisiae. The maximum temperatures for growth of L. pentosus and L. plantarum were 41.9 and 43.0 °C, respectively; while for W. anomalus and C. boidinii they were 38.2 and 36.5 °C. The optimum temperatures for growth were also higher for L. pentosus and L. plantarum (35.5 and 32.9 °C), compared to W. anomalus and C. boidinii (29.3 and 26.9 °C, respectively). Additional experiments carried out in natural olive brines confirmed previous results, showing that high NaCl concentrations clearly favoured yeast growth and that at high temperatures LAB slightly overcame yeasts. Results obtained in this paper could be useful for industry for a better control of both table olive fermentation and packaging.     

Isolation and characterisation of lactic acid bacteria strains from raw camel milk for potential use in the production of fermented Tunisian dairy products

The aim of this work was to study the suitability of camel milk for the production of dairy products by lactic acid fermentation. Sixty strains of lactic acid bacteria (LAB) were isolated from camel milk. The strains were tested for their acidification activity, ability to use citrate, exopolysaccharide production, lipolytic, proteolytic activities and resistance to antibiotics. Ten strains were investigated for their ability to metabolize carbohydrates and that resulted in the identification of 5 Lactococcus lactis, 1 Lactobacillus pentosus, 2 Lactobacillus plantarum, 1 Lactobacillus brevis and 1 Pediococcus pentosaceus strains. Two strains of Lactococcus lactis SCC133 and SLch14 were selected to produce traditional Tunisian fermented dairy products (Lben, Raib, Jben cheese and Smen). These strains were chosen based on their acid production capacity and their ability to produce a high yield of biomass.     

Bacterial community dynamics,lactic acid bacteria species diversity and metabolite kinetics of traditional Romanian vegetable fermentations

BACKGROUND: Artisanal vegetable fermentations are very popular in Eastern European countries. Fresh vegetables undergo a spontaneous fermentation in the presence of salt, which is mainly carried out by lactic acid bacteria (LAB). RESULTS: Culture‐dependent and culture‐independent analyses of end‐samples of various spontaneous vegetable fermentations carried out in houses of the Chiodju region (central Romania) revealed Lactobacillus plantarum and Lactobacillus brevis as the most frequently isolated LAB species. Leuconostoc mesenteroides and Leuconostoc citreum were also found. Furthermore, the community dynamics of spontaneous cauliflower and mixed‐vegetable (green tomatoes, carrots and cauliflower) fermentations revealed three steps: an initial phase characterised by the presence of Enterobacteriaceae and a wide LAB species diversity, encompassing Weissella species; a second phase from day 3 onwards wherein L. citreum and Lb. brevis occurred; and a final phase characterised by the prevalence of Lb. brevis and Lb. plantarum. Metabolite target analysis revealed that glucose and fructose were mostly depleted at the end of fermentation. The main products of carbohydrate metabolism were lactic acid, acetic acid, ethanol and small amounts of mannitol, indicating heterolactate fermentation. CONCLUSION: Given their prevalence at the end of vegetable fermentations, Lb. brevis and Lb. plantarum appear to be good candidate starter cultures for controlled vegetable fermentation processes. © 2012 Society of Chemical Industry     

Adaptability of lactic acid bacteria and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava and use of competitive strains as starters

The adaptability of lactic acid bacteria (LAB) and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava was investigated using PCR-DGGE and bacteriological culture combined with rRNA gene sequence analysis. Sourdoughs were prepared either from flours of the cereals wheat, rye, oat, barley, rice, maize, and millet, or from the pseudocereals amaranth, quinoa, and buckwheat, or from cassava, using a starter consisting of various species of LAB and yeasts. Doughs were propagated until a stable microbiota was established. The dominant LAB and yeast species were Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus paralimentarius, Lactobacillus plantarum, Lactobacillus pontis, Lactobacillus spicheri, Issatchenkia orientalis and Saccharomyces cerevisiae. The proportion of the species within the microbiota varied. L. paralimentarius dominated in the pseudocereal sourdoughs, L. fermentum, L. plantarum and L. spicheri in the cassava sourdough, and L. fermentum, L. helveticus and L. pontis in the cereal sourdoughs. S. cerevisiae constituted the dominating yeast, except for quinoa sourdough, where I. orientalis also reached similar counts, and buckwheat and oat sourdoughs, where no yeasts could be detected. To assess the usefulness of competitive LAB and yeasts as starters, the fermentations were repeated using flours from rice, maize, millet and the pseudocereals, and by starting the dough fermentation with selected dominant strains. At the end of fermentation, most of starter strains belonged to the dominating microbiota. For the rice, millet and quinoa sourdoughs the species composition was similar to that of the prior fermentation, whereas in the other sourdoughs, the composition differed.     

Evolution of fermenting microbiota in tarhana produced under controlled technological conditions

The purpose of this study was to evaluate the evolution of lactic acid bacteria (LAB) and yeasts during the fermentation of tarhana produced with some pasteurised ingredients and carried out at 30 and 40 °C. The chemical parameters were those typical for tarhana production. Coliform bacteria were not detected during fermentation, while LAB and yeasts were in the range 10⁷-10⁸ colony forming units (CFU) g⁻¹. Plate counts showed an optimal development of both fermenting microbial groups and the differences in cell concentrations were not significant (P > 0.05). LAB were isolated during fermentation and grouped on the basis of phenotypic and polymorphic characteristics. LAB isolates were identified by a combined genetic approach consisting of 16S/23S rRNA intergenic spacer region (ITS) and partial 16S rRNA gene sequencing as Pediococcus acidilactici, Lactobacillus plantarum and Lactobacillus brevis. Hence, the pasteurisation of the vegetable ingredients, excluded wheat flour, enhanced the hygienic conditions of tarhana without influencing the normal evolution of LAB. However, the fermentation at 40 °C favoured pediococci, while the production at 30 °C was mainly characterised by lactobacilli. Yeasts, identified by the restriction fragment length polymorphism (RFLP) of the 5.8S ITS rRNA gene, were mainly represented by the species Saccharomyces cerevisiae in both productions.     

Lactobacillus pentosus dominates spontaneous fermentation of Italian table olives

Culture-dependent and -independent approaches were applied to identify the bacterial species involved in Italian table olive fermentation. Bacterial identification showed that Lactobacillus pentosus was the dominant species although the presence of Lactobacillus plantarum, Lactobacillus casei, Enterococcus durans, Lactobacillus fermentum and Lactobacillus helveticus was observed. Rep-PCR allowed to obtain strain-specific profiles and to establish a correlation with table olive environment. PCR-DGGE (Denaturing Gradient Gel Electrophoresis) confirmed the heterogeneity of bacterial community structure in fermented table olives as well as the prevalence of L. pentosus. The strains were characterized on the basis of technological properties (NaCl tolerance, β-glucosidase activity and the ability to grow in synthetic brine and in presence of 1 g/100 mL oleuropein). L. pentosus showed a high capacity of adaptation to the different conditions characterizing the olive ecosystem. This species showed the highest percentage of strains able to grow in presence of 10 g/100 mL NaCl, oleuropein and in the synthetic brine. Moreover, all the strains belonging to L. pentosus and L. plantarum species showed a β-glucosidase activity. This study allowed both to identify the main species and strains associated to Italian table olives and to obtain a lactic acid bacteria collection to apply as starter culture in the process of olive fermentation.     

Taxonomic structure of the yeasts and lactic acid bacteria microbiota of pineapple (Ananas comosus L. Merr.) and use of autochthonous starters for minimally processing

Pichia guilliermondii was the only identified yeast in pineapple fruits. Lactobacillus plantarum and Lactobacillus rossiae were the main identified species of lactic acid bacteria. Typing of lactic acid bacteria differentiated isolates depending on the layers. L. plantarum 1OR12 and L. rossiae 2MR10 were selected within the lactic acid bacteria isolates based on the kinetics of growth and acidification. Five technological options, including minimal processing, were considered for pineapple: heating at 72 °C for 15 s (HP); spontaneous fermentation without (FP) or followed by heating (FHP), and fermentation by selected autochthonous L. plantarum 1OR12 and L. rossiae 2MR10 without (SP) or preceded by heating (HSP). After 30 days of storage at 4 °C, HSP and SP had a number of lactic acid bacteria 1000 to 1,000,000 times higher than the other processed pineapples. The number of yeasts was the lowest in HSP and SP. The Community Level Catabolic Profiles of processed pineapples indirectly confirmed the capacity of autochthonous starters to dominate during fermentation. HSP and SP also showed the highest antioxidant activity and firmness, the better preservation of the natural colours and were preferred for odour and overall acceptability.     

Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus predominate during well-performed Malaysian cocoa bean box fermentations,underlining the importance of these microbial species for a successful cocoa bean fermentation process

Two spontaneous Malaysian cocoa bean box fermentations (one farm, two plantation plots) were investigated. Physical parameters, microbial community dynamics, yeast and bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the respective fermented dry cocoa beans. Similar microbial growth and metabolite profiles were obtained for the two fermentations. Low concentrations of citric acid were found in the fresh pulp, revealing low acidity of the raw material. The main end-products of the catabolism of the pulp substrates glucose, fructose, and citric acid by yeasts, LAB, and AAB were ethanol, lactic acid, acetic acid, and/or mannitol. Hanseniaspora opuntiae, Lactobacillus fermentum, and Acetobacter pasteurianus were the prevalent species of the two fermentations. Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus pentosus, and Acetobacter ghanensis were also found during the mid-phase of the fermentation processes. Leuconostoc pseudomesenteroides and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Tatumella saanichensis and Enterobacter sp. were present in the beginning of the fermentations and they could be responsible for the degradation of citric acid and/or the production of gluconic acid and lactic acid, respectively. The presence of facultative heterofermentative LAB during the fermentations caused a high production of lactic acid. Finally, as these fermentations were carried out with high-quality raw material and were characterised by a restricted microbial species diversity, resulting in successfully fermented dry cocoa beans and good chocolates produced thereof, it is likely that the prevailing species H. opuntiae, S. cerevisiae, Lb. fermentum, and A. pasteurianus were responsible for it.     

Characterization of Proteolytic Effect of Lactic Acid Bacteria Starter Cultures on Thai Fermented Sausages

The objective of this study was to investigate the effect of starter culture addition on proteolysis of Thai fermented sausages. Sausages inoculated with six different external starter cultures—Pediococcus pentosaceous, Pediococcus acidilactici, Weissella cibaria, Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus sakei—were compared with naturally fermented sausages. The results of microbiological analysis indicated that the dominance of lactic acid bacteria (LAB) could inhibit the growth of pathogens and spoilage. Proteolysis was observed during fermentation by the reduction of myofibrillar and sarcoplasmic proteins and the increase in nonprotein nitrogen (NPN) and total free amino acids. The highest increase in concentration of NPN and free amino acids was obtained from sausages inoculated with LAB. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed a similar pattern of proteolysis of sarcoplasmic proteins in all sausages, while that of the inoculated sausages with L. plantarum, L. pentsus, and L. sakei exhibited increased degradation of myofibrillar protein bands at 200 and 45 kDa.     

Effect of lactic acid fermentation on antioxidant, texture, color and sensory properties of red and green smoothies

Weissella cibaria, Lactobacillus plantarum, Lactobacillus sp. and Lactobacillus pentosus were variously identified from blackberries, prunes, kiwifruits, papaya and fennels by partial 16S rRNA gene sequence. Representative isolates from each plant species were screened based on the kinetics of growth on fruit juices. A protocol for processing and storage of red and green smoothies (RS and GS) was set up, which included fermentation by selected lactic acid bacteria starters and exo-polysaccharide producing strains. Starters grew and remained viable at ca. 9.0 log cfu g⁻¹ during 30 days of storage at 4 °C. No contaminating Enterobacteriaceae and yeast were found throughout storage. Values of soluble solids, total titratable acidity and viscosity distinguished started RS and GS compared to spontaneously (unstarted) fermented smoothies. Color difference dE∗_ab and browning index were positively affected by lactic acid fermentation. Consumption of carbohydrates by lactic acid bacteria was limited as well as it was the lactic fermentation. Consumption of malic acid was evident throughout storage. Polyphenolic compounds and, especially, ascorbic acid were better preserved in started RS and GS compared to unstarted samples. This reflected on the free radical scavenging activity. A statistical correlation was only found between the level of ascorbic acid and free radical scavenging activity. As shown by a ?rst-order equation, the rate of degradation of ascorbic acid through storage were found to be higher in the unstarted compared to started RS and GS. Fermentation by lactic acid bacteria clearly improved the sensory attributes of RS and GS.     

The effects of baobab pulp powder on the micro flora involved in tempe fermentation

Locally prepared tempe that underwent natural fermentation was characterized by the growth of Lactobacillus plantarum, Streptococcus lactis , Bacillus sp., Salmonella sp., Klebsiella sp., Lactococcus lactis , Rhizopus sp. and Staphylococcus sp., while fermentation carried out with the addition of varying levels of baobab pulp powder had mainly lactic acid bacteria (LAB)— Lactobacillus plantarum, Lactobacillus fermentum , Lactobacillus acidophilus and Rhizopus sp. dominating. Increasing concentrations of baobab pulp powder led to an increase in the population of lactic acid bacteria (LAB) from 2.3×10² to 3.3×10⁴ while it reduced the population of inoculated Rhizopus from 10² to only six colonies on malt extract agar (MEA).     

Enhancement of survival of probiotic and non-probiotic lactic acid bacteria by yeasts in fermented milk under non-refrigerated conditions

The effects of yeasts on the survival of probiotic and non-probiotic lactic acid bacteria (LAB) were studied in fermented milk under non-refrigerated conditions (30 °C) with a view to develop ambient-stable fermented milk with live LAB. Five yeasts tested (Saccharomyces bayanus, Williopsis saturnus var. saturnus, Yarrowia lipolytica, Candida kefyr and Kluyveromyces marxianus) enhanced the survival of Lactobacillus bulgaricus (but not Streptococcus thermophilus) in a mixed yoghurt culture in yoghurt by ~ 10² to 10⁵-fold. Seven yeasts examined (Candida krusei, Geotrichum candidum, Pichia subpelliculosa, Kloeckera apiculata, Pichia membranifaciens, Schizosaccharomyces pombe and Y. lipolytica) improved the survival of Lactobacillus rhamnosus in fermented milk by ~ 10³ to 10⁶-fold. W. saturnus var. saturnus enhanced the survival of Lactobacillus acidophilus, L. rhamnosus (probiotic) and Lactobacillus reuteri by up to 10⁶-fold, but the same yeast failed to improve the survival of Lactobacillus johnsonii (probiotic), S. thermophilus and L. bulgaricus in fermented milk. These results provide definitive evidence that yeasts possess stability-enhancing effects on LAB and that the specific effects of yeasts on LAB stability vary with yeasts as well as with LAB. However, the molecular mechanism of such interaction of yeasts with LAB remains to be found.     

Spontaneous organic cocoa bean box fermentations in Brazil are characterized by a restricted species diversity of lactic acid bacteria and acetic acid bacteria

Spontaneous organic cocoa bean box fermentations were carried out on two different farms in Brazil. Physical parameters, microbial growth, bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the fermented dry cocoa beans. The main end-products of the catabolism of the pulp substrates (glucose, fructose, and citric acid) by yeasts, LAB, and AAB were ethanol, lactic acid, mannitol, and/or acetic acid. Lactobacillus fermentum and Acetobacter pasteurianus were the predominating bacterial species of the fermentations as revealed through (GTG)₅-PCR fingerprinting of isolates and PCR-DGGE of 16S rRNA gene PCR amplicons of DNA directly extracted from fermentation samples. Fructobacillus pseudoficulneus, Lactobacillus plantarum, and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Also, three novel LAB species were found. This study emphasized the possible participation of Enterobacteriaceae in the cocoa bean fermentation process. Tatumella ptyseos and Tatumella citrea were the prevailing enterobacterial species in the beginning of the fermentations as revealed by 16S rRNA gene-PCR-DGGE. Finally, it turned out that control over a restricted bacterial species diversity during fermentation through an ideal post-harvest handling of the cocoa beans will allow the production of high-quality cocoa and chocolates produced thereof, independent of the fermentation method or farm.     

Characterization of Lactobacillus isolates from fermented olives and their bacteriocin gene profiles

Near one hundred isolates of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum from table olives were studied. Strains were genotyped by rep-PCR. Although the technique failed to differentiate some isolates at the species level, it proved a robust and easy procedure that could be useful for distinguishing between related strains of L. paraplantarum, L. pentosus and L. plantarum from a large pool of unrelated strains of these species. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnB, plnC, plnD, plnE/F, plnF, plnI, plnJ, plnK, plnG and plnN in most isolates of the three species. Sequences of bacteriocin genes present in L. paraplantarum and L. pentosus were homologous to L. plantarum genes. Through a discriminating analysis of the bacteriocin gene profiles, it was possible to establish a relationship between the origin of isolation and the LAB isolates, regardless of species.     

Potential of lactic acid bacteria to improve the fermentation and quality of coffee during on‐farm processing

This study describes, for the first time, the potential use of selected lactic acid bacteria (LAB) to conduct improved coffee bean fermentation during on‐farm wet processing. Among different strains tested, Lactobacillus plantarum LPBR01 showed a suitable production of organic acids and flavour‐active esters in a coffee‐pulp simulation medium and was used as starter culture under field conditions. The results indicated that L. plantarum LPBR01 was able to establish an accelerated coffee‐pulp acidification process and potentially reduced the fermentation time from 24 to 12 h. The inoculation of LPBR01 strain also increased significantly the formation of volatile aroma compounds during fermentation process (such as ethyl acetate, ethyl isobutyrate and acetaldehyde) and enabled the production of beverage with distinct sensory notes and a remarkable increase in quality compared to the conventional process. Our results suggest that the use of LAB in coffee processing is an ideal alternative way to conduct faster and improved coffee bean fermentation.     

Development of fermented instant Chinese noodle using Lactobacillus plantarum

A new-type of instant Chinese noodle was developed with the application of lactic acid fermentation by lactobacilli. Since the pH value of the noodle sheets is alkaline with kansui (around 8.5), alkaline tolerance is required for the lactobacilli to ferment noodle sheets. The screening of the lactobacilli strains suitable for the fermentation was conducted using 46 strains from 12 species (including subspecies) of lactobacilli. Several strains of Lactobacillus pentosus and Lactobacillus plantarum were found to be fermenters. Among these, L. plantarum NRIC 0380, that showed the highest fermentation rate and favorable modification of noodle, was selected as the best strain, and was employed for the pilot scale manufacture of instant Chinese noodle. During fermentation, L. plantarum NRIC 0380 produced lactic acid to about 11 g/kg noodle sheet after 24 h with a concomitant pH decrease from an initial of about 7.9 down to 3.9. Sensory test after rehydration with boiled water revealed that the fermented instant Chinese noodle sheets at pH 7.5 had increased hardness, elasticity and light sour taste.     

Diversity of bacteria and yeast in the naturally fermented cotton seed and rice beverage produced by Brazilian Amerindians

Microorganisms associated with the fermentation of cotton seed and rice were studied using a combination of culture-dependent and -independent methods. Samples of the cotton seed and rice beverage were collected every 8 h during the fermentation process for analysis of the microbiota present over 48 h. The lactic acid bacteria (LAB) population reached values of approximately 8.0 log cfu/mL. A total of 162 bacteria and 81 yeast isolates were identified using polyphasic methods. LAB (Lactobacillus plantarum, Lactobacillus vermiforme, Lactobacillus paracasei) were the most frequently isolated bacteria. Bacillus subtilis was present from 16 h until the end of the fermentation process. A decrease in pH value from 6.92 (0 h) to 4.76 (48 h) was observed, and the concentration of lactic acid reached 24 g/L at the end of the fermentation process. DGGE (denaturing gradient gel electrophoresis) was performed to determine the dynamics of the communities of bacteria and yeast, and the analysis revealed a predominance of LAB throughout the fermentation process. No changes were observed in the yeast community. The yeast species detected were Candida parapsilosis, Candida orthopsilosis, Clavispora lusitaniae and Rhodotorula mucilaginosa. Our studies indicate that the DGGE technique combined with a culture-dependent method is required to discern the dynamics in the fermentation of cotton seed and rice.     

A review on traditional Turkish fermented non-alcoholic beverages: Microbiota,fermentation process and quality characteristics

Shalgam juice, hardaliye, boza, ayran (yoghurt drink) and kefir are the most known traditional Turkish fermented non-alcoholic beverages. The first three are obtained from vegetables, fruits and cereals, and the last two ones are made of milk. Shalgam juice, hardaliye and ayran are produced by lactic acid fermentation. Their microbiota is mainly composed of lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus paracasei subsp. paracasei in shalgam fermentation and L. paracasei subsp. paracasei and Lactobacillus casei subsp. pseudoplantarum in hardaliye fermentation are predominant. Ayran is traditionally prepared by mixing yoghurt with water and salt. Yoghurt starter cultures are used in industrial ayran production. On the other hand, both alcohol and lactic acid fermentation occur in boza and kefir. Boza is prepared by using a mixture of maize, wheat and rice or their flours and water. Generally previously produced boza or sourdough/yoghurt are used as starter culture which is rich in Lactobacillus spp. and yeasts. Kefir is prepared by inoculation of raw milk with kefir grains which consists of different species of yeasts, LAB, acetic acid bacteria in a protein and polysaccharide matrix. The microbiota of boza and kefir is affected from raw materials, the origin and the production methods.