Construction of in situ degradation bacteria of corn straw and analysis of its degradation efficiency

Abstract

Purpose The highly efficient degradation bacteria were selected from the humus from the very cold straw in China for many years to construct the in situ degradation bacteria, and the degradation efficiency of corn straw was determined by process optimization. Methods According to the main components of corn straw, through morphological, physiological, and biochemical screening, three highly efficient complementary degradation strains were selected to construct the compound flora, and the degradation efficiency was analyzed by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Result The corn straw selected in this paper is mainly composed of cellulose (31.99%), hemicellulose (25.33%), and lignin (14.67%). Through the determination of enzyme activity, strain Streptomyces sp. G1T has high decomposition ability to cellulose and hemicellulose but weak utilization ability to lignin; strain Streptomyces sp. G2T has the strongest decomposition ability to cellulose and hemicellulose among the three strains. The decomposition ability of strain Streptomyces sp. G3T to lignin was the strongest among the three strains. Therefore, by compounding the three strains, the decomposition ability has been greatly improved. The optimal process conditions obtained by single factor and response surface method are as follows: pH is 7, temperature is 30 °C, inoculation amount is 5%, rotational speed is 210 rpm, and the weight loss rate of straw is 60.55% after decomposing for 7 days. A large amount of degradation of corn straw can be seen by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Conclusion Streptomyces sp. G1T, Streptomyces sp. G2T, and Streptomyces sp. G3T screened from straw humus in very cold areas were used to construct in situ degradation bacteria, which had good straw degradation activity and had the potential to be used for straw treatment in cold areas after harvest. This characteristic makes the complex bacteria become a strong competitive candidate for industrial production, and it is also an effective biotechnology in line with the current recycling of resources.

Effects of maize straw treated with various levels of CaO and moisture on composition, structure, and digestion by in vitro gas production

“…Consequently, the surface of straw becomes rough, collapsed and many fragmented [21]. Highly efficient bacterial strains from humus were used to degrade maize straw [1]. By increasing the time allowed for degradation, the waxy silicified layer of maize straw was gradually thinned and disappeared.…”

“…At present, in China, a fraction of maize straw is used in manufacturing paper, board and other industrial raw materials while most of the maize straw is burned or thrown away, resulting in significant waste of natural resources. Discarding the straw by burning and dumping in the field does not only affect the air quality critically, but also aggravates the greenhouse gas emission [ 1 ].…”

Effect of liquid volume and microflora source on degradation rate and microbial community in corn stover degradation

“…Under natural conditions, the degradation of straw depends on the synergistic action of multiple microorganisms (Liang et al 2020 ; Wang et al 2016 ). Microbial consortia can improve the efficiency and stability of straw degradation compared to a single strain (Gong et al 2020 ; Zuroff and Curtis 2012 ). Many microbial consortia with high cellulose-degrading activity have been obtained by combination or domestication (Chu et al 2021 ; Kato et al 2005 ).…”

“…and Curvibacter zj. 35 120 10 % NaOH 78.10 15 (Zhang et al 2018 ) Enriched from corn field soil 30 0 1.5 % NaOH 66.1 10 (Deng et al 2017 ) BGC-1, enriched from industrial sugarcane bagasse pile 50 200 10 % NaOH 72 4 (Wongwilaiwalin et al 2013 ) Enriched from feces and sludge 50 0 Steam-exploded 62 7 (Zhang et al 2012 ) CSS-1, enriched from sugarcane bagasse compost 50 0 Alkali-peracetic acid 70 7 (Wongwilaiwalin et al 2010 ) Consisting of three Streptomyces 30 210 NO 60.55 7 (Gong et al 2020 ) GF-20, enriched from soil and cow dung 30 0 NO 59.47 60 (Qinggeer et al 2016 ; Yu et al 2019 ) Consisting of Pelomonas gx. and Curvibacter zj.…”

“…Microbial consortia can improve the e ciency and stability of straw degradation compared to a single strain (Gong et al 2020;Zuroff and Curtis 2012). Many microbial consortia with high cellulose-degrading activity have been obtained by combination or domestication (Chu et al 2021;Kato et al 2005).…”