Abstract
In this study, with the aim of determining and assessing the influence of several culture conditions on the ligninolytic enzyme (LiP, MnP, and Lac) activity of bacteria, five lignin-degrading bacteria strains were isolated from two different soil samples and cultured on minimum salt medium agar containing alkaline lignin (MSML agar). Among the five isolated strains, DL1 and X3 expressed strong and stable ligninase enzyme activity at various temperature levels (30°C, 37°C, 50°C, and 60°C) and were selected for further study. Notably, at 60°C, the ligninase activity of both strains lasted until the seventh day before decreasing. The effects of the culture medium conditions, namely, carbohydrate sources, nitrogen sources, and pH, on the ligninolytic system illustrated that both X3 and DL1 were able to generate good enzymatic activity at a pH range of 3.0 to 7.0. These strains could use various sources of carbohydrates and nitrogen, derived from glucose, lactose, peptone, meat extract, and yeast extract. In addition, the analyses of biochemical characteristics revealed that X3 was capable of hydrolyzing starch and cellulose, while DL1 was not. Therefore, the results of this study suggested the potential of applying selected lignin-degrading bacterial strains on lignin treatments of agricultural wastes.
Highlights
Vietnam is a country that has good conditions for agricultural production and has become one of the largest exporters in the world for specific goods such as rice, coffee, cashew seeds, corn, and fruits
The soil samples were collected from the Xuan Lien Natural Conservation Area in Thanh Hoa province and the composting unit of the Research Center For Medicinal Plants (RCMP), National Institute of Medicinal Materials (NIMM), in Hanoi to isolate the bacterial strains that had ligninolytic enzymes
The effects of temperature levels on the ligninase enzymes of these strains were checked by incubation at temperatures of 30 C, 37 C, 50 C, and 60 C, and evaluated by qualitative assay for LiP and quantitative assay for both manganese peroxidase (MnP) and Lac activities
Summary
Vietnam is a country that has good conditions for agricultural production and has become one of the largest exporters in the world for specific goods such as rice, coffee, cashew seeds, corn, and fruits. Agricultural residues are waste substances that arise from cultivation, animal husbandry, and aquaculture. Cultivation releases an enormous amount of dry biomass from plants such as rice straw, rice bran, sugarcane bagasse, sawdust, corn stoves, and coconut shells, etc. These residues are comprised of lignocellulose, the most abundant resource of organic material in the world, which is composed of lignin, cellulose, and hemicellulose. Lignin compounds are the hardest to break down for most organisms because of their complex, heterogeneous structure (Wong, 2009)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
