PDF(Pubmed)
Abstract：
Degradation of crop straw in natural environment has been a bottleneck. There has been a recent increase in the exploration of cold-adapted microorganisms as they can solve the problem of corn straw degradation under low temperatures and offer new alternatives for the sustainable development of agriculture. The study was conducted in low-temperature (10°C) and high-efficiency cellulose-degrading bacteria were screened using carboxymethyl cellulose (CMC) selection medium and subjected to genome sequencing by the third-generation Pacbio Sequl and the second-generation Illumina Novaseq platform, and their cellulase activity was detected by 3,5-dinitrosalicylic acid (DNS) method. The results showed that the low-temperature (10°C) and high-efficiency cellulose-degrading bacterium Bacillus subtilis K1 was 4,060,823 bp in genome size, containing 4,213 genes, with 3,665, 3,656, 2,755, 3,240, 1,261, 3,336 and 4,003 genes annotated in the non-redundant protein sequence database (NR), Pfam, clusters of orthologous groups of proteins (COGs), Genome Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Annotation databases, respectively. In addition, a large number of lignocellulose degradation-related genes were annotated in the genome. The cellulose activity of B. subtilis K1 was higher, exhibiting the highest activity of endo-β-glucanase (24.69 U/ml), exo-β-glucanase (1.72 U/ml) and β-glucosaccharase (1.14 U/ml). It was found that through adding cold-adapted cellulose-degrading bacteriaK1 in the corn straw composting under 6°C (ambient temperature), the average temperature of straw composting was 58.7°C, and higher 86.7% as compared to control. The HA/FA was higher 94.02% than the control and the lignocellulose degradation rate was lower 18.01-41.39% than the control. The results provide a theoretical basis for clarifying the degradation potential of cold-adapted cellulose-degrading bacteria and improving the cellulose degradation efficiency.
摘要：
农作物秸秆在自然环境中的降解一直是瓶颈。最近对冷适应微生物的探索有所增加，因为它们可以解决低温下玉米秸秆降解的问题，并为农业的可持续发展提供新的替代方案。该研究是在低温（10°C）下进行的，使用羧甲基纤维素（CMC）选择培养基筛选了高效纤维素降解菌，并通过第三代PacbioSequl和第二代IlluminaNovaseq平台进行了基因组测序，用3,5-二硝基水杨酸(DNS)法检测其纤维素酶活性。结果表明,低温(10℃)高效纤维素降解菌枯草芽孢杆菌K1基因组大小为4,060,823bp,含有4,213个基因，在非冗余蛋白质序列数据库（NR）中注释了3,665,3,656,2,755,3,240,1,261,3,336和4,003个基因，普法姆,直系同源蛋白质组(COG)的簇，基因组本体论（GO），京都基因和基因组百科全书（KEGG），和注释数据库，分别。此外,在基因组中注释了大量与木质纤维素降解相关的基因。枯草芽孢杆菌K1的纤维素活性较高，表现出最高活性的内切β-葡聚糖酶（24.69U/ml），外-β-葡聚糖酶(1.72U/ml)和β-葡糖化酶(1.14U/ml)。发现通过在6°C（环境温度）下在玉米秸秆堆肥中添加冷适应的纤维素降解细菌K1，秸秆堆肥平均温度为58.7℃,和高于对照组的86.7%。HA/FA比对照高94.02%,木质纤维素降解率比对照低18.01-41.39%。研究结果为阐明冷适应纤维素降解菌的降解潜力和提高纤维素降解效率提供了理论依据。
