Dilip R. Ranade

Extractive butanol fermentation with non-ionic surfactant, a recently explored area, has shown promising results with several advantages but is relatively less investigated. This work reports the extractive fermentation with selected non-ionic surfactants (L62 and L62D) to enhance butanol production using a high-butanol producing strain (Clostridium beijerinckii MCMB 581). Biocompatibility studies with both the surfactants showed growth. Higher concentrations of surfactant (>5%) affected the cell count. 15.3 g L⁻¹ of butanol and 21 g L⁻¹ of total solvents were obtained with 3% (v/v) L62 which was respectively, 43% (w/w) and 55% (w/w), higher than control. It was found that surfactant addition at 9th h doubled the productivity (from 0.13 to 0.31 g L⁻¹ h⁻¹ and 0.17 to 0.39 g L⁻¹ h⁻¹, respectively for butanol and total solvent). Butanol productivity obtained was 2–3 times higher than similar studies on extractive fermentation with non-ionic surfactants. Interestingly, mixing did not improve butanol production.

Plackett-Burman and Response Surface Methodology were used to optimize fermentation medium for enhancing butanol production by Clostridium beijerenckii strain CHTa. Optimization using Plackett-Burman design showed yeast extract, MgSO4.7H2O and glucose to have significant impact over other factors, namely (NH4)2SO4, CaCO3, FeSO4.7H2O, cysteine hydrochloride, sodium thioglycolate and pH. To find out the optimal concentrations and interactions between the selected factors, further experiments were

The human gut microbiome is important for maintaining the health status of the host. Clostridia are key members of the human gut microbiome, carrying out several important functions in the gut environment. Hence understanding the role of different Clostridium species isolated from human gut is essential. The present study was aimed at investigating the role of novel Clostridium sp. isolate BL8 in human gut using genome sequencing as a tool.

Two coccoid, non-motile, obligately anaerobic, Gram-stain-negative bacteria, occurring singly or in pairs, or as short chains, with a mean size of 1.4–2.5 µm were isolated from the faeces of two healthy human volunteers, aged 26 and 56 years, and were designated NMBHI-10^T and BLPYG-7, respectively. Both the strains were affiliated to the sub-branch Sporomusa of the class Clostridia as revealed by 16S rRNA gene sequence analysis. The isolates NMBHI-10^T and BLPYG-7 showed 99.1 and 99.2 % 16S rRNA gene sequence similarity, respectively, with Megasphaera elsdenii JCM 1772^T. DNA–DNA hybridization and phenotypic analysis showed that both the strains were distinct from their closest relative, M. elsdenii JCM 1772^T (42 and 53 % DNA–DNA relatedness with NMBHI-10^T and BLPYG-7, respectively), but belong to the same species (DNA–DNA relatedness of 80.9 % between the isolates). According to DNA–DNA hybridization results, the coccoid strains belong to the same genospecies, and neither is related to any of the recognized species of the genus Megasphaera . Strains NMBHI-10^T and BLPYG-7 grew in PYG broth at temperatures of between 15 and 40 °C (optimum 37 °C), but not at 45 °C. The strains utilized a range of carbohydrates as sources of carbon and energy including glucose, lactose, cellobiose, rhamnose, galactose and sucrose. Glucose fermentation resulted in the formation of volatile fatty acids, mainly caproic acid and organic acids such as succinic acid. Phylogenetic analysis, specific phenotypic characteristics and/or DNA G+C content also differentiated the strains from each other and from their closest relatives. The DNA G+C contents of strains NMBHI-10^T and BLPYG-7 are 57.7 and 54.9 mol%, respectively. The major fatty acids were 12 : 0 FAME and 17 : 0 CYC FAME. On the basis of these data, we conclude that strains NMBHI-10^T and BLPYG-7 should be classified as representing a novel species of the genus Megasphaera , for which the name Megsphaera indica sp. nov. is proposed. The type strain is NMBHI-10^T ( = DSM 25563^T = MCC 2481^T).

Background: The gut micro flora plays vital role in health status of the host. The majority of microbes residing in the gut have a profound influence on human physiology and nutrition. Different human ethnic groups vary in genetic makeup as well as the environmental conditions they live in. The gut flora changes with genetic makeup and environmental factors and hence it is necessary to understand the composition of gut flora of different ethnic groups. Indian population is different in physiology from western population (YY paradox) and thus the gut flora in Indian population is likely to differ from the extensively studied gut flora in western population. In this study we have investigated the gut flora of two Indian families, each with three individuals belonging to successive generations and living under the same roof. Results: Denaturation gradient gel electrophoresis analysis showed age-dependant variation in gut microflora amongst the individuals within a family. Different bacterial genera were dominant in the individual of varying age in clone library analysis. Obligate anaerobes isolated from individuals within a family showed age related differences in isolation pattern, with 27% (6 out of 22) of the isolates being potential novel species based on 16S rRNA gene sequence. In qPCR a consistent decrease in Firmicutes number and increase in Bacteroidetes number with increasing age was observed in our subjects, this pattern of change in Firmicutes / Bacteroidetes ratio with age is different than previously reported in European population. Conclusion: There is change in gut flora with age amongst the individuals within a family. The isolation of high percent of novel bacterial species and the pattern of change in Firmicutes /Bacteroidetes ratio with age suggests that the composition of gut flora in Indian individuals may be different than the western population. Thus, further extensive study is needed to define the gut flora in Indian population.