Ancient Bacterial Class Alphaproteobacteria Cytochrome P450 Monooxygenases Can Be Found in Other Bacterial Species

Cytochrome P450 monooxygenases (CYPs/P450s), heme-thiolate proteins, are well-known players in the generation of chemicals valuable to humans and as a drug target against pathogens. Understanding the evolution of P450s in a bacterial population is gaining momentum. In this study, we report comprehensive analysis of P450s in the ancient group of the bacterial class Alphaproteobacteria. Genome data mining and annotation of P450s in 599 alphaproteobacterial species belonging to 164 genera revealed the presence of P450s in only 241 species belonging to 82 genera that are grouped into 143 P450 families and 214 P450 subfamilies, including 77 new P450 families. Alphaproteobacterial species have the highest average number of P450s compared to Firmicutes species and cyanobacterial species. The lowest percentage of alphaproteobacterial species P450s (2.4%) was found to be part of secondary metabolite biosynthetic gene clusters (BGCs), compared other bacterial species, indicating that during evolution large numbers of P450s became part of BGCs in other bacterial species. Our study identified that some of the P450 families found in alphaproteobacterial species were passed to other bacterial species. This is the first study to report on the identification of CYP125 P450, cholesterol and cholest-4-en-3-one hydroxylase in alphaproteobacterial species (Phenylobacterium zucineum) and to predict cholesterol side-chain oxidation capability (based on homolog proteins) by P. zucineum.     

Effect of moisture content on oil extraction from spent coffee grounds

Spent coffee grounds (SCG) were used in this study for oil extraction. It was observed that oil extraction increased with water content up to 20 wt% for non-polar solvents and up to 40 wt% for polar solvents. At 80 wt% moisture, no oil was observed instead a black gel was formed. Oil extraction was observed to increase with time but it was concluded that increasing extraction time beyond 60 min had no significant benefit for both solvents (ethanol and toluene). The highest amount of oil extracted was observed when using ethanol at 40 wt% moisture and it was around 20%. The saponification values for oil extracted from SCG were observed to be between 175 and 180 but were lower than those obtained for soybean (193). The SCG oil was observed to contain the following fatty acids in this quantity order: palmitic> linoleic acid > stearic acid.