黄酒米曲霉菌种的培养研究

米曲霉培养条件对种曲质量有较大影响,文章以米曲霉为菌种,研究了培养时间和加水量与种曲产孢子数的关系。     

我国葡萄属野生种形态学特性的研究

本文对我国２２个野生葡萄种或变种，９０多个株系的颜色、绒毛、叶及果实等形态学特性进行了观察研究。结果表明，中国野生葡萄植物形态丰富多样，并建议对目前有关葡萄描述记载标准作进一步修订和完善，以适应我国野生葡萄资源研究利用工作的开展。     

米曲霉三角瓶菌种培养的改进

酿造酱油离不开试管菌种以及三角瓶菌种培养,种好、曲好、酱油好,出率也高。已是每个酿造职工都知的道理。多年来我曾对米曲霉的三角瓶菌种培养作了探索,特别对水份与三角瓶菌种生长之间的因果关系,经过不断试验研究,提高了三角瓶菌种的质量。 以往在酿造厂,三角瓶菌种的一般做法是:面粉20克与麸皮80克同时搅拌均匀后润水,然后装瓶灭菌,培养72小时。笔者认为,麸皮比面粉易于吸水而且面粉容易结     

红曲米中七株红曲霉纯培养的分离鉴定

从广西武宣地区的红曲米中分纯得到7株红曲霉纯培养。初步鉴定分属3类:M-1、M-2、M-6属于紫色红曲霉类,M-4、M-5属于红色红曲霉类,M-3、M-7属于丛毛状红曲霉类。发现M-1菌株具有较为突出的红曲色素产生能力,通过形态观察和耐酒精、耐NaCl实验,对M-1菌株进行了种的鉴定。     

两株米曲霉菌种的发酵性能研究

将2株米曲霉扩大培养后用于生产试验,并将其发酵酱油的性能进行对比。结果表明,米曲霉1号酱油的氨基酸态氮、pH值、A530 nm、总氮低于米曲霉2号菌,总酸高于米曲霉2号;米曲霉2号酱油的游离氨基酸总含量为6.05 g/100 mL,是米曲霉1号（4.18 g/100 mL）的1.45倍;米曲霉1号酱油中醇类物质、酸类物质和醚类物质相对含量分别达61.53%、14.16%和1.26%,高于米曲霉2号的57.3%、13.07%和0.46%,而酯类物质（3.73%）、酮类物质（1.83%）和醛类物质（16.33%）低于米曲霉2号的3.96%、1.95%和21.31%;米曲霉1号酱油香气浓郁偏醇香味,米曲霉2号酱油香气浓郁偏酯香;米曲霉2号酱油的加热沉淀达到204 mm2,远高于米曲霉1号酱油的25 mm2。加热后过滤可去除米曲霉2号酱油中的沉淀。     

红曲霉液体菌种培养特性动态分析

通过对FF-6202红曲霉液体菌种在发酵过程中的几个动态参数的研究,分析了还原糖、糖化力、pH值、菌丝量、色价和色调等主要参数在红曲发酵过程中的变化规律。初步确定了在液体种子培养过程中的几个关键控制参数是:还原糖、pH值、菌丝量和色价。     

米曲霉M3产蛋白酶特性研究

对比了本课题组从自然发酵的豆酱中分离的三株蛋白酶活力较高的菌株，对其中蛋白酶活力最高的菌株M3的菌丝和孢子形态进行了观察，初步判断为米曲霉，并对其培养条件进行了探索。结果表明：M3在培养基组成为麸皮：葡萄糖：水=9：1：5的条件下，接种3mL孢子菌悬液，28℃培养72h时酶活最高。     

白曲霉斜面菌种培养条件的优化

对麸曲酱香白酒生产所需糖化酶菌种:白曲霉的一级种培养工艺条件进行单因素试验,应用Minitab15软件设计了Plack-ett-Burman筛选试验,通过筛选得出蔗糖浓度、硫酸铵浓度、培养基pH值以及微量元素配比为菌种生长的4个显著性影响因素,并对此进行正交试验得出白曲霉一级种斜面培养的最优条件为蔗糖浓度25g/L,硫酸铵浓度3.5g/L,MgSO4.7H2O 1.0g/L,KCl 1.0g/L,K2PO4 1.0g/L,琼脂15g/L,pH值5.5,培养温度28℃,菌体糖化酶活力724.8U/g。     

栖土曲霉蛋白酶特性研究

本主要研究了栖土曲霉液体培养时产蛋白酶的属性，探讨了其最佳发酵方式，并研究了液体发酵时最佳培养基配比和培养条件。研究表明：液体发酵培养时中性蛋白酶活力最高，此栖土曲霉适合液态发酵培养，液态发酵时最佳培养基配比为麸皮3％，米糠1％，玉米粉1％，K2HPO40．4％，最适培养温度为28～30℃、培养时间为72hr、接种量为8％。     

红曲霉菌种的筛选

本实验通过平板分离和紫外诱变两种方法对红曲霉菌种进行了筛选,选出的红曲霉菌种产色能力强、稳定性好,其产色率比出发菌株提高了32%。     

Plackett-Burman设计在曲霉Aspergillus sp.GX-0010果糖基转移酶发酵条件主要因子筛选中的应用

试验采用Plackett-Burman试验设计,选取蔗糖、蛋白胨、硫酸亚铁、pH值、温度、培养时间、装液量,接种量共8个相关因素进行设计,统计分析表明,pH(p=0.019)、温度(p=0.003)、装液量(p=0.131)为对曲霉(Aspergillus sp.)菌株GX-0010产果糖基转移酶具有显著影响的因素。     

曲霉羧肽酶的分离纯化研究

采用 (NH4) 2 SO4、酒精、DE52 和SephadexG1 0 0对AspergillusspCP 1发酵液进行分离纯化 ,并检测在分离纯化过程中酶的回收率和比活力 ,最后用SDS PAGE电泳检验酶的纯度。确定 (NH4) 2 SO4饱和浓度在 60 %～ 90 %之间 ,酒精浓度为 3 5 %～ 70 %之间用于粗酶液的提纯 ;电泳得到一个清晰的条带。它们的分子质量约为 15 942u。     

曲霉菌酶学性质的研究

研究本实验室保存的2种曲霉my-1及my-2的特性，讨论了时间、温度、pH对曲霉菌产酶的影响，并对酶的适宜反应温度、pH及酶的热稳定性和pn稳定性进行了探讨。     

乳酸杆菌肽聚糖的分离鉴定及其免疫活性

研究了乳酸杆菌细胞壁肽聚糖的分离、鉴定及其对肽聚糖生物活性的影响.实验获得了SDS处理粗细胞壁的适宜条件为SDS质量浓度8g/dL,处理时间为沸水浴10min.SDS结合胰蛋白酶和TCA处理,可有效去除乳酸杆菌中的非共价结合蛋白质及共价结合蛋白质.经化学分析鉴定,所提取的乳酸杆菌成分为肽聚糖,肽聚糖中丙氨酸、天冬氨酸、谷氨酸和赖氨酸浓度分别为1.181,0.943,0.770和0.456mmol/g,是肽聚糖中的组分氨基酸.SDS结合TCA处理,方能较有效地去除DNA.TCA处理是去除细胞壁磷壁酸、脂磷壁酸的有效方法.此外,小白鼠腹腔巨噬细胞的吞噬实验、C3b受体实验以及血清溶菌酶活力实验证实,所分离纯化肽聚糖的免疫学活性未受影响.     

Biochemical characterisation and application of lipases produced by Aspergillus sp. on solid‐state fermentation using three substrates

Lipase from Aspergillus sp. obtained by solid‐state fermentation (SSF) on wheat bran (LWB), soybean bran (LSB) and soybean bran combined with sugarcane bagasse (LSBBC) were 67.5, 58 and 57.3 U of crude lipase per gram substrate, respectively. The optimum pH of activity and stability of the LWB was between 8 and 9, and the optimum temperature of activity and stability was 50 °C and up to 60 °C, respectively. The LSB and LSBBC showed two peaks of optimum pH (4 and 6) and optimal values of temperature and stability at 50 °C. The LSB was stable in the pH range of 6–7, while LSBBC in the range of pH 4–7. All the enzymes show activities on p‐nitrophenyl esters (butyrate, laurate and palmitate). LWB stood out either on the hydrolysis of sunflower oil, presenting 66.1% of the activity over commercial lipase and on the esterification of oleic acid and ethanol, surpassing the activities of the commercial lipases studied. The thin layer chromatography showed that LWB and LSB have produced ethyl esters from corn oil, while LWB produced it from sunflower oil.     

利用米曲霉制作腊八豆的研究

以酿造酱油用的米曲霉经紫外线诱变选育后，人工接种于煮熟的黄豆制作腊八豆。结果表明，接种量为熟豆重量的0．5％(孢了含量10^10个／g菌剂)，经32～35℃、48h前发酵便可得优质霉豆胚，加适量食盐、食用白酒及生姜等拌匀入坛进行10～15d的后发酵，便可获得品质极鲜美，食后余味甘甜的腊八豆，优于毛霉型腊八豆，更优于传统方法制作的腊八豆。比传统腊八豆的制作周期缩短近1个月，便于工业化生产。     

曲霉T3-5-1产单宁酶培养条件优化

以通过60Co 诱变得到的曲霉T3-5-1 为实验菌株,通过单因素与正交试验,对其产单宁酶的条件进行研究。结果表明：以β- 环糊精为碳源、蛋白胨为氮源、培养基初始pH 值为5.5、单宁酸质量分数为3.5%、接菌量为5%、摇瓶培养转速120r/min、250mL 三角锥瓶中装液50mL 培养基、培养温度30℃的培养条件为曲霉T3-5-1 的最佳产单宁酶条件。在此条件下,曲霉T3-5-1 产单宁酶比活力达到202.16U/mL,比优化前提高约4 倍。     

胞外弹性蛋白酶的理化特性及其影响因素

分离得到的假单胞菌(Pseudomonas sp) 菌株具有较强的分泌胞外弹性蛋白酶的能力。经微生物发酵方法生产的弹性蛋白酶,经过盐析、透析、DEAE SephadexA2 5离子交换层析、SephadexG75凝胶过滤层析等纯化步骤,从其发酵液中得到了均一的酶制品。研究结果表明,酶的最适作用温度为5 0℃;在硼砂-硼酸缓冲液中最适作用pH为8 0左右;酶在碱性环境下( pH7 0～12 0 )稳定性较好;在37℃以下,酶的稳定性较高。超过6 0℃,酶在短时间内即失活     

Evaluation of aflatoxin and Aspergillus sp. contamination in raw peanuts and peanut-based products along this supply chain in Malaysia

The peanut supply chain in Malaysia is dominated by three main stakeholders (importers, manufacturers, retailers). The present study aimed to determine the levels and critical points of aflatoxin and fungal contamination in peanuts along the supply chain. Specifically, two types of raw peanuts and six types of peanut-based products were collected (N = 178). Samples were analysed for aflatoxins by using high-performance liquid chromatography. Results revealed that the aflatoxin contamination was significantly higher (P ≤ 0.05) in raw peanuts and peanut-based products from the retailers. However, there was no significant difference (P ≥ 0.05) in fungal contamination for both types of peanuts except for the total fungal count in raw peanuts from the retailers. Furthermore, raw peanut kernels from the retailers were the most contaminated ones ranged from <LOD to 1021.4 µg/kg (mean: 120.7 µg/kg, median: 1.4 µg/kg) followed by the samples collected from the manufacturers which was ranged from < LOD to 181.9 µg/kg (mean: 20.5 µg/kg, median: 0.0 µg/kg). About 38% and 22% of the samples from the retailers and manufacturers were found to have exceeded the Malaysian Regulation limit (raw peanuts:15 µg/kg; peanut-based products:10 µg/kg), respectively. In contrast, no aflatoxins were detected in samples from the importers. On the other hand, 15.0% and 5.9% of peanut-based products from retailers and manufacturers, respectively, were found to have exceeded the limit. Fungal contamination (0.3–3.6 log CFU/g) was relatively higher in raw peanuts compared to that of peanut-based products (0.6–2.7 log CFU/g). In conclusion, the manufacturers and retailers were the critical points for aflatoxin contamination in peanuts. However, fungal contamination was more critical in the raw peanuts compared to peanut-based products. The study was limited by a minimal number of samples from the importer. Therefore, further investigations on a larger sample size should be conducted to confirm the findings in this present study.     

吸附菌体的霉菌筛选试验

探索出一种新的吸附发酵液中菌体的方法。以曲霉菌作为试验菌株对异养小球藻发酵液进行吸附试验,通过霉菌筛选试验找出一株吸附效果良好的黑曲霉,并得出最佳的吸附条件为发酵液初始糖含量3.0 g/100 mL,小球藻初始质量浓度10.0 g/L,在此条件下接种后24～72 h霉菌的吸附能力最强,发酵液的质量浓度下降38.69%,吸光度值下降32.34%。通过酵母菌发酵液试验黑曲霉的吸附效果得到进一步验证。