The biodegradation of coal discard is being intensively studied in South Africa in an effort to develop passive methods for the successful revegetation and rehabilitation of waste dumps, to mitigate pollution, and facilitate mine closure. Bacteria were isolated from slurries of coal tailings and diesel-contaminated soil, screened for coal biodegradation competence, characterized, and the colonization and degradation of coal discard and geologically weathered coal investigated using individual isolates and consortia. Ten novel coal-degrading bacterial strains were isolated and characterized, the gene sequences deposited with GenBank, and the (wild-type) strains deposited at Microbial Culture Collection, India. The results from the present work show that bituminous coal discard and geologically weathered coal is used by these isolates as carbon and energy source. Isolated strains and consortia colonized and degraded both coal substrates. Growth rate of the isolates is faster and stationery phase achieved sooner in minimal medium containing geologically weathered coal. This observation suggests that the oxygen-rich weathered coal is a more friable substrate and thus readily colonised and biodegraded. A reduction in mass of substrate is demonstrated for both individual isolates and consortia. The changes in pH and associated media colouration occurred concomitant with formation of humic acid-like (HS) and fulvic acid-like substances (FS) which is confirmed following analysis of these products by FT-IR spectroscopy. It is concluded that preferential metabolism of alkanes from the coal substrates provided the carbon and energy for bacterial growth and transformation of the substrates to HS and FS.

南非正在深入研究废弃煤的生物降解，以开发消极方法，成功地对垃圾场进行植被恢复和修复，以减轻污染并促进矿山关闭。从煤尾矿和被柴油污染的土壤的泥浆中分离细菌，筛选煤炭的生物降解能力，并进行了表征，并使用单独的分离物和联合体调查了废弃煤和地质风化煤的定殖和降解。分离并鉴定了十种新型的可降解煤的细菌菌株，其基因序列由GenBank保藏，而（野生型）菌株则保藏在印度微生物培养所。目前工作的结果表明，这些分离物将烟煤丢弃物和地质风化煤用作碳和能源。分离的菌株和财团在两个煤基质上定殖并降解。在含有地质风化煤的基本培养基中，分离株的生长速度更快，固定期更快。该观察结果表明，富氧的风化煤是更易碎的基质，因此易于定殖和生物降解。对于单独的分离物和联合体，底物质量都得到了降低。pH值的变化和相关介质的着色伴随腐殖酸样（HS）和黄腐酸样物质（FS）的形成而发生，这是通过FT-IR光谱分析对这些产物进行确认的。