Metabolic Pathways in Biodegrading Psychrotrophic Bacteria Under Cold Environments

Solid waste management is the major concern in the Himalayan region due to relatively cold climate, rapid urbanization, a substantial rise in consumption patterns, over-crowded tourist destinations, and illegal dumping. Biodegradable organic waste is a major portion of solid waste, but due to harsh and prolonged winter, processes, like composting and vermicomposting, are considered inefficient. The limited microbial population on the onset of degradation, low temperature, and moisture level, inefficient proteo-lingo-cellulolytic microbes hinders the composting process. The low temperatures limit the initial microbial load and hence pose technical challenges by extending the mesophilic phase and shortening the thermophilic stage. Psychrotrophic bacteria that can synthesize cold-active extracellular enzymes carry out efficient catalysis of biological reactions under conditions where the mesophilic counterparts cannot function. Cold-tolerant bacteria are hence known to be more valuable in aerobic degradation of organic matter under low temperatures and are very suitable in the organic waste treatment system. The decay of materials during composting follows the common biochemical pathways to recycle the nutrients. This chapter discusses the metabolic pathways in biodegrading psychrotrophic bacteria at low temperatures. Generally, plant or animal-based waste and food waste forms a rich organic source for compost mix. The degradation of these organic compounds involves various enzymes discussed in this chapter with special emphasis on cellulase, amylase, pectinase, xylanase, and protease.