Efficient degradation of rice straw through a novel psychrotolerant Bacillus cereus at low temperature

Abstract

BACKGROUND: Rice straw (RS) is one of the largest sources of lignocellulosic, which is an abundant raw material for biofuels and chemicals. However, the natural degradation of RS under a low temperature environment is the biggest obstacle to returning straw to the field. RESULTS:In the present study, one bacillus strain W118 was isolated. Strain W118 was identified as Bacillus cereus through morphological and physiological characterization and 16S rDNA sequencing. The optimum growth temperature and pH of strain W118 were 20 °C and 6.5, respectively. Simultaneously, it was found that the strain W118 grew well at low temperature, even at a temperature of 4 °C (OD 600 = 1.40 ± 0.01). The decrease of various compositions of RS after the fermentation process at a temperature of 20 °C and 4 °C for 14 days was 27.00 ± 0.02% and 23.70 ± 0.04%, respectively. The composition of RS decreased to 50.71 ± 0.02% after being fermented at 4 °C for 25 days. The results of scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction of RS showed that the compositions of RS were significant decreased.CONCLUSION: This test suggests that the strain W118 is efficient for degrading RS at low temperature, which has great application potential for straw degradation in a low temperature area.

Study on the degradation conditions of corn stalks by Asian corn borer digestive enzymes combined with white-rot fungus

“…Whereas the degradation conditions, such as temperature, pH, time, and so on, could affect the metabolic ability of white-rot fungi to produce enzymes, thus affecting the degradation effect. 19,20 Wang et al 21 explored that the degradation impact of white-rot fungi could be affected by short-term pre-exposure to silver ions.…”

Isolation and Characterization of a Low-Temperature, Cellulose-Degrading Microbial Consortium from Northeastern China

“…For example, Boboua et al (2023) suggest that the low-temperature-resistant microbial consortium LTF-27 is the most hydrolytic and acidifying bacterial consortium for corn straw degradation, with the effects of hydrolytic substrate concentration, initial pH, and inoculum quantity investigated using single-factor testing and response surface methodology [ 19 ]. Another case has been reported based on Bacillus cereus strain W118, which demonstrated effective rice straw degradation at temperatures as low as 4 °C, showing high potential for straw degradation in a low temperature environment [ 20 ]. Another low-temperature, high-efficiency cellulose-degrading bacterium ( Bacillus subtilis K1) was detected with endo-β-glucanase, exo-β-glucanase, and β-glucosaccharase activities at 10 °C [ 14 ].…”