Isolation, identification, and community diversity of microorganisms during tank fermentation of Liupao tea

Tank fermentation is a novel approach to fermenting teas; however, the species of microorganisms present remain unclear. The microbial community composition of Liupao tea at various stages of tank fermentation was analyzed using high-throughput sequencing. Sphingomonas, Aquabacterium, Pelomonas, Acinetobacter, Blastobotrys, Aspergillus, Debaryomyces, and Aureobasidium were the predominant genera, which is different from pile fermentation. Fifteen genera (including Lactobacillus, Debaryomyces, Candida, Allobaculum, Flavobacterium, Caulobacter, Blastobotrys, Aspergillus, and Rasamsonia) were identified as biomarkers. PICRUSt analysis predicted that the most abundant functional genes were related to metabolism of carbohydrates, amino acids, cofactors, vitamins, and other secondary metabolites. Using the pure culture method, 283 strains were isolated at various stages of fermentation, representing 20 genera and 29 species of bacteria, and 11 genera and 18 species of fungi. Most of the dominant Sphingomonas, Staphylococcus, Aspergillus, and Blastobotrys identified by sequencing were also isolated. Of these, Sphingomonas olei, Aspergillus luchuensis, Aspergillus niger, Aspergillus aculeatus, Aspergillus amstelodami, Blastobotrys adeninivorans, Candida metapsilosis, and Candida blankii were beneficial strains that might be used to ferment Liupao tea. This study provides a basis for the development of processing technologies and utilization of microbial strains in the production of dark teas. PRACTICAL APPLICATION: Microbial diversity in tank-fermented Liupao tea was reported for the first time. 8 microorganisms were the predominant genera. The species, functions and potential risks of microorganisms was revealed. We clarified the differences between tank and pile fermentation.

Marine Fungal and Bacterial Isolates for Lipase Production: A Comparative Study

Lipases, belonging to the class of enzymes called hydrolases, can catalyze triglycerides to fatty acids and glycerol. They are produced by microbes of plant and animal origin, and also by marine organisms. As marine microorganisms thrive in extreme conditions, lipases isolated from their origin possess characteristics of extremozymes, retain its activity in extreme conditions and can catalyze few chemical reactions which are impossible otherwise relative to the lipase produced from terrestrial microorganisms. Lipases are useful in many industries like detergent, food, leather, pharmaceutical, diary, etc. Few commercial enzymes have been developed and the use of them in certain industries like dairy, soaps are proved to be beneficial. There are few research papers reporting the production of lipase from marine bacteria and fungi. Lipase production involves two types of fermentation processes-solid-state fermentation (SSF) and submerged fermentation (SmF). Although SmF process is used conventionally, SSF process produces lipase in higher amounts. The production is also influenced by the composition of the medium, physiochemical parameters like temperature, pH, carbon, and nitrogen sources.