Enzyme Production-Based Approach for Determining the Functions of Microorganisms within a Community

Abstract

The functions of specific microorganisms in a microbial community were investigated during the composting process. Cerasibacillus quisquiliarum strain BLx T and Bacillus thermoamylovorans strain BTa were isolated and characterized in our previous studies based on their dominance in the composting system. Strain BLx T degrades gelatin, while strain BTa degrades starch. We hypothesized that these strains play roles in gelatinase and amylase production, respectively. The relationship between changes in the abundance ratios of each strain and those of each enzyme activity during the composting process was examined to address this hypothesis. The increase in gelatinase activity in the compost followed a dramatic increase in the abundance ratio of strain BLx T . Zymograph analysis demonstrated that the pattern of active gelatinase bands from strain BLx T was similar to that from the compost. Gelatinases from both BLx T and compost were partially purified and compared. Homologous N-terminal amino acid sequences were found in one of the gelatinases from strain BLx T and that of compost. These results indicate strain BLx T produces gelatinases during the composting process. Meanwhile, the increase in the abundance ratio of strain BTa was not concurrent with that of amylase activity in the compost. Moreover, the amylase activity pattern of strain BTa on the zymogram was different from that of the compost sample. These results imply that strain BTa may not produce amylases during the composting process. To our knowledge, this is the first report demonstrating that the function of a specific microorganism is directly linked to a function in the community, as determined by culture-independent and enzyme-level approaches.

Bacterial community dynamics during reduction of odorous compounds in aerated pig manure slurry

“…2002; Haruta et al. 2005), and newly isolated strains that are possibly responsible for organic waste degradation have been reported (Nakamura et al. 2004).…”

Activity and Phylogenetic Composition of Proteolytic Bacteria in Mesophilic Fed-batch Garbage Composters

“…Members of Actinobacteria have been shown to predominate in the steady-state mesophilic FBC process 13,23) . Particular species of Bacillus have been shown to constitute a significant proportion of the total population in this process 13,23) and to predominate and have major roles in protein digestion in thermophilic FBC reactors 10,21) . Nevertheless, there is still a possibility that other bacteria are involved in protein decomposition in the FBC process, because more diverse groups of protease than expected from the data on the isolates actually take part in the process as shown by zymography.…”

“…One of the most important extracellular enzymes associated with the decomposition of biowaste is protease. Recently a change in gelatinase activity during the operation of a FBC process was studied by zymography with negative activity staining 21) . Nevertheless, information about the physiological features and diversity of proteolytic bacteria in the FBC process is still lacking.…”

Microbial Community Structure and Dynamics of Dark Fire-Cured Tobacco Fermentation

“…The traditional technology of Toscano cigar tobacco fermentation is based on a semicontinuous process whose physicalchemical profile suggests a model resembling that of the wellknown solid waste composting process (11,23,39,51,52), being characterized by intrinsic variation of chemical and physical parameters. Major sources of variability are the local heterogeneity of the bulk, the seasonal fluctuation of temperature, and inconstant shuffling times, all reflecting the small-scale, semiartisanal, nonstandardized nature of the tobacco fermentation process.…”