Abstract

The vast metabolic potential of microbes in brown coal (lignite) processing and utilization can greatly contribute to innovative approaches to sustainable production of high-value products from coal. In this study, the multi-faceted and complex coal biosolubilization process by Bacillus sp. RKB 7 isolate from the Kazakhstan coal-mining soil is reported, and the derived products are characterized. Lignite solubilization tests performed for surface and suspension cultures testify to the formation of numerous soluble lignite-derived substances. Almost 24% of crude lignite (5% w/v) was solubilized within 14 days under slightly alkaline conditions (pH 8.2). FTIR analysis revealed various functional groups in the obtained biosolubilization products. Analyses of the lignite-derived humic products by UV-Vis and fluorescence spectrometry as well as elemental analysis yielded compatible results indicating the emerging products had a lower molecular weight and degree of aromaticity. Furthermore, XRD and SEM analyses were used to evaluate the biosolubilization processes from mineralogical and microscopic points of view. The findings not only contribute to a deeper understanding of microbe–mineral interactions in coal environments, but also contribute to knowledge of coal biosolubilization and bioconversion with regard to sustainable production of humic substances. The detailed and comprehensive analyses demonstrate the huge biotechnological potential of Bacillus sp. for agricultural productivity and environmental health.

摘要

褐煤（褐煤）加工和利用中微生物的巨大代谢潜能可以极大地促进采用创新方法可持续利用煤炭生产高价值产品。在这项研究中，芽孢杆菌的多方面和复杂的煤炭生物增溶过程sp。报道了从哈萨克斯坦煤矿土壤中分离到的RKB 7，并对产物进行了表征。对表面和悬浮培养物进行的褐煤增溶测试证明形成了许多可溶的褐煤衍生物质。在弱碱性条件下（pH 8.2）在14天内将近24％的粗褐煤（5％w / v）溶解。FTIR分析揭示了所获得的生物增溶产物中的各种官能团。通过UV-Vis和荧光光谱法对褐煤衍生的腐殖质产品的分析以及元素分析得出兼容的结果，表明新兴产品的分子量和芳香度较低。此外，XRD和SEM分析被用于从矿物学和微观角度评估生物增溶过程。这些发现不仅有助于加深对煤炭环境中微生物与矿物之间相互作用的理解，而且有助于了解关于可持续生产腐殖质的煤炭生物增溶和生物转化的知识。详尽而全面的分析证明了其巨大的生物技术潜力。芽孢杆菌属。为农业生产力和环境健康。