Production Of Organic Compounds Research Articles

Evolution of Thermophilic Microbial Communities from a Deep-Sea Hydrothermal Chimney under Electrolithoautotrophic Conditions with Nitrate.

Recent studies have shown the presence of an abiotic electrical current across the walls of deep-sea hydrothermal chimneys, allowing the growth of electroautotrophic microbial communities. To understand the role of the different phylogenetic groups and metabolisms involved, this study focused on electrotrophic enrichment with nitrate as electron acceptor. The biofilm density, community composition, production of organic compounds, and electrical consumption were monitored by FISH confocal microscopy, qPCR, metabarcoding, NMR, and potentiostat measurements. A statistical analysis by PCA showed the correlation between the different parameters (qPCR, organic compounds, and electron acceptors) in three distinct temporal phases. In our conditions, the Archaeoglobales have been shown to play a key role in the development of the community as the first colonizers on the cathode and the first producers of organic compounds, which are then used as an organic source by heterotrophs. Finally, through subcultures of the community, we showed the development of a greater biodiversity over time. This observed phenomenon could explain the biodiversity development in hydrothermal contexts, where energy sources are transient and unstable.

Organic Compounds Generated in Bioethanol Production from Agave Bagasse

In bioethanol production through lignocellulosic residues fermentations are generated by-products such as organic compounds (OCs). The organic compounds (OCs) had been well studied in wine and beer industry, but little is known about their presence in bioethanol industry, even when these affect yeasts physiologic state, and are considered as economically desirable in the chemical industry. In this work was evaluated the production of OCs in bioethanol production processes through separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) of different agave bagasse residue (ABR). Fermentations were carried out by the Kluyveromyces marxianusSLP1, K. marxianus OFF1 and Saccharomyces cerevisiaeEthanol Red yeasts strains. The main OCs detected were ethyl acetate, methanol, 1-propanol, isobutanol, butanol, isoamyl-alcohol, ethyl-lactate, furfuryl-alcohol, phenyl-acetate, and 2-phenyl ethanol. A higher number of OCs was found in the SSF process when were used the K. marxianusOFF1 and SLP1 yeasts. This study provides better knowledge of the kind and concentrations of OCs produced by fermentation of the lignocellulosic ABR, which allow propose bioethanol by-products as potential source of economically desirable compounds.

STUDYING REPRESENTATIVES OF WHEAT GRAIN MICROBIOTA RESISTANT TO COPPER, ZINC, MANGANESE AND IODINE SALTS

There was studied the species composition of the wheat grain microbiota, representatives of which could be potential producers of organic compounds for modern biotechnology. Twenty wheat (Triticum vulgaris) samples were tested, from microbiocenoses of which the strains of heterotrophic microorganisms resistant to toxic concentrations of copper, zinc, manganese and iodine salts were isolated and described. The contents of zinc, manganese and copper salts in a suspension of washed bacterial cells were determined using a highly sensitive multielement analysis method of inductively coupled plasma mass spectrometry (ICP-MS). Using media containing manganese, we isolated and identified Stenotrophomonas maltophilia, Bacillus cereus, Lactococcus lactis, Bacillus subtilis, Brevibacillus sp., Bacillus amyloliquefaciens. Using a medium containing 1% KJ, we isolated Vagococcus sp., Paenibacillus dendritiformis and three unidentified isolates. On a nutrient medium containing copper sulfate, one isolate of an unknown species was grown. In the presence of 1% zinc sulfate, Klebsiella pneumonia, Enterococcus faecalis, Enterococcus faecium, Ralstonia insidiosa, Stenotrophomonas maltophilia have grown that allows using them for the development of selective media. Bacteria of the genus Bacillus have been detected, which are characterized by the ability to accumulate copper compounds to a concentration of 22.3 mg/g dry biomass. The 16S rRNA gene fragment from this culture has the greatest, but incomplete (98%), homology with Bacillus sp. LY (Genbank AY787805). No data on species identity of this Bacillus strain are available in the literature studied that allows us to refer it and isolated strain Cu2 to a new species, which has not previously been described.