Characteristics and mechanisms of guar gum degradation by indigenous bacteria in coal seams

Authors

LI Bing, School of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, China; School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, ChinaFollow
GUO Hongyu, School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, China; Science and Technology R & D Platform of Emergency Management Ministry for Deep Well Ground Control and Gas Extraction Technology, Henan Polytechnic University, Jiaozuo 454003, ChinaFollow
ZHOU Xiao, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710021, China
WANG Haichao, School of Geology and Mining Engineering, Xinjiang University, Urumqi 830047, China
JIAN Kuo, School of Energy and Materials Engineering, Taiyuan University of Science and Technology, Taiyuan 030000, China
CHEN Zhaoying, State Key Laboratory of Coal and CBM Co-mining, Jincheng 048000, China
ZHANG Bin, Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China

Abstract

Background Hydraulic fracturing serves as a stimulation technique extensively used in the commercial development of coalbed methane (CBM), in which guar gum is commonly used as a fracturing fluid thickener. However, under the low-temperature conditions of coal reservoirs, conventional chemical gel-breaking methods often suffer from incomplete gel breaking and high residue content, resulting in formation damage and a decrease in the production efficiency of CBM wells. Methods Using indigenous bacteria in coal seams as functional strains, this study conducted microbial gel-breaking experiments. It systematically investigated the characteristics of guar gum biodegradation by these bacteria and determined the dominant microbial taxa responsible for guar gum degradation. Results and Conclusions Indigenous bacteria in coal seams achieved the complete degradation of guar gum, meeting the gel-breaking requirement of fracturing fluids (viscosity≤5 mPa·s). Concurrently, they also reduced both the content and particle size of residues, effectively alleviating the potential formation damage induced by insoluble residues during the gel breaking of guar gum fracturing fluids. Guar gum was primarily hydrolyzed by indigenous bacteria into soluble polysaccharides, thereby reducing viscosity and achieving gel breaking. Analysis of microbial community structures revealed that Bacteroidota and Spirochaetota were the dominant functional phyla involved in guar gum degradation. Functional prediction using PICRUSt2 (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2) indicated that the guar gum degradation was primarily attributed to the synergistic activities of α-galactosidase (EC 3.2.1.22), β-mannosidase (EC 3.2.1.25), and β-mannanase (EC 3.2.1.78). Among these, β-mannanase exhibited the most pronounced increase in gene abundance, suggesting its central role in gel-breaking of guar gum. Furthermore, environmental factors directly influenced gel-breaking efficiency of guar gum, with the highest degradation efficiency occurring at 45 ℃ and pH 6.0. Despite the inhibitory effect of high salinity on guar gum degradation, the indigenous bacteria retained gel-breaking capability even at a salinity of 40 g/L. This study elucidates the degradation mechanism of guar gum by indigenous bacteria in coal seams and identifies the impact patterns of environmental factors on microbial gel-breaking performance. These findings provide a theoretical basis for the application of indigenous bacteria-based biological gel-breaking technology in CBM extraction.

Keywords

guar gum, indigenous bacteria in coal seams, microbial gel breaking, environmental factors, coalbed gas bioengineering

DOI

10.12363/issn.1001-1986.25.07.0494

Recommended Citation

LI Bing, GUO Hongyu, ZHOU Xiao, et al. (2026) "Characteristics and mechanisms of guar gum degradation by indigenous bacteria in coal seams," Coal Geology & Exploration: Vol. 54: Iss. 2, Article 11.
DOI: 10.12363/issn.1001-1986.25.07.0494
Available at: https://cge.researchcommons.org/journal/vol54/iss2/11

Reference

[1] 王耀锋,何学秋,王恩元,等. 水力化煤层增透技术研究进展及发展趋势[J]. 煤炭学报,2014,39(10):1945−1955

WANG Yaofeng,HE Xueqiu,WANG Enyuan,et al. Research progress and development tendency of the hydraulic technology for increasing the permeability of coal seams[J]. Journal of China Coal Society,2014,39(10):1945−1955

[2] 鲜保安,夏柏如,张义,等. 开发低煤阶煤层气的新型径向水平井技术[J]. 煤田地质与勘探,2010,38(4):25−29

XIAN Baoan,XIA Bairu,ZHANG Yi,et al. Technical analysis on radial horizontal well for development of coalbed methane of low coal rank[J]. Coal Geology & Exploration,2010,38(4):25−29

[3] HUANG Qiming,LIU Shimin,WANG Gang,et al. Coalbed methane reservoir stimulation using guar–based fracturing fluid:A review[J]. Journal of Natural Gas Science and Engineering,2019,66:107−125.

[4] 兰浩,杨兆彪,仇鹏,等. 新疆准噶尔盆地白家海凸起深部煤层气勘探开发进展及启示[J]. 煤田地质与勘探,2024,52(2):13−22

LAN Hao,YANG Zhaobiao,QIU Peng,et al. Exploration and exploitation of deep coalbed methane in the Baijiahai uplift,Junggar Basin:Progress and its implications[J]. Coal Geology & Exploration,2024,52(2):13−22

[5] 戴彩丽,赵辉,梁利,等. 煤层气井用锆冻胶压裂液低温破胶体系[J]. 天然气工业,2010,30(6):60−63

DAI Caili,ZHAO Hui,LIANG Li,et al. A low temperature breaking system for zirconium gel fracturing fluids in coalbed methane gas wells[J]. Natural Gas Industry,2010,30(6):60−63

[6] 王泽鹏. 温度–瓦斯–压裂液作用下深部煤岩微观结构演化及力学特性研究[D]. 重庆：重庆大学，2022.

WANG Zepeng. Microstructure evolution and mechanical properties of deep coal under the combined action of temperature，gas and fracturing fluid[D]. Chongqing：Chongqing University，2022.

[7] 吴磊. 水基压裂液低温破胶技术的研究[D]. 西安：西安石油大学，2019.

WU Lei. Study on low temperature gel breaking technology of water–based fracturing fluid[D]. Xi’an：Xi’an Shiyou University，2019.

[8] 曹功泽,冯云,林军章,等. 油田聚合物解堵生物酶制剂的研究进展[J]. 南京工业大学学报(自然科学版),2024,46(2):131−140

CAO Gongze,FENG Yun,LIN Junzhang,et al. Oilfield polymer–unblocking enzymes:State of the art and perspectives[J]. Journal of Nanjing Tech University (Natural Science Edition),2024,46(2):131−140

[9] 马鑫. 储层压裂液伤害的微生物及酶修复机理研究[D]. 东营：中国石油大学(华东)，2019.

MA Xin. Research on the mechanism of microbial and enzymatic remediation of fracturing fluid formation damage[D]. Dongying：China University of Petroleum (East China)，2019.

[10] 李慧玲. 高产β–甘露聚糖酶菌株选育、构建及其酶学特性研究[D]. 哈尔滨：东北林业大学，2014.

LI Huiling. Breeding and construction of the strain of high–producing beta–mannanase and its enzymatic characteristics[D]. Harbin：Northeast Forestry University，2014.

[11] SITTERLEY K A,SILVERSTEIN J,ROSENBLUM J,et al. Aerobic biological degradation of organic matter and fracturing fluid additives in high salinity hydraulic fracturing wastewaters[J]. Science of the Total Environment,2021,758:143622.

[12] MA Xin,WANG Zhihui,DA Qi’an,et al. Application of guar gum degrading bacteria in microbial remediation of guar–based fracturing fluid damage[J]. Energy & Fuels,2017,31(8):7894−7903.

[13] 苏现波,夏大平,赵伟仲,等. 煤层气生物工程研究进展[J]. 煤炭科学技术,2020,48(6):1−30

SU Xianbo,XIA Daping,ZHAO Weizhong,et al. Research advances of coalbed gas bioengineering[J]. Coal Science and Technology,2020,48(6):1−30

[14] FLORES R M,RICE C A,STRICKER G D,et al. Methanogenic pathways of coal–bed gas in the Powder River Basin,United States:The geologic factor[J]. International Journal of Coal Geology,2008,76(1/2):52−75.

[15] GUO Hongyu,SHI Shangwei,LI Guofu,et al. Biodegradation of guar gum and its enhancing effect on biogas production from coal[J]. Fuel,2022,311:122606.

[16] LI Bing,GUO Hongyu,CHEN Zhenhong,et al. Metabolism mechanisms of biogenic methane production by synergistic biodegradation of lignite and guar gum[J]. Science of the Total Environment,2024,946:174085.

[17] 王金梦,孙春晓,吴勃,等. 酶法制备瓜尔胶水解物的体外酵解特性分析[J]. 食品研究与开发,2024,45(6):90−98

WANG Jinmeng,SUN Chunxiao,WU Bo,et al. In vitro fermentation characteristics of guar gum hydrolysate prepared by enzymatic method[J]. Food Research and Development,2024,45(6):90−98

[18] WANG Jie,HUANG Yixiao,ZHANG Yan,et al. Study of fracturing fluid on gel breaking performance and damage to fracture conductivity[J]. Journal of Petroleum Science and Engineering,2020,193:107443.

[19] 张传保,王彦玲,陈孟鑫,等. 耐高温胍胶压裂液及其对储层的伤害机理研究进展[J]. 化工进展,2022,41(11):5912−5924

ZHANG Chuanbao,WANG Yanling,CHEN Mengxin,et al. Research progress on high temperature resistant guar gum fracturing fluid and its damage mechanism to reservoirs[J]. Chemical Industry and Engineering Progress,2022,41(11):5912−5924

[20] QIU Liewei,SHEN Yiding,WANG Chen,et al. Scanning electron microscopy analysis of guar gum in the dissolution,gelation and gel–breaking process[J]. Polymer Testing,2018,68:95−99.

[21] 郭建春,何春明. 压裂液破胶过程伤害微观机理[J]. 石油学报,2012,33(6):1018−1022

GUO Jianchun,HE Chunming. Microscopic mechanism of the damage caused by gelout process of fracturing fluids[J]. Acta Petrolei Sinica,2012,33(6):1018−1022

[22] ZHAO Weizhong,SU Xianbo,ZHANG Yifeng,et al. Microbial electrolysis enhanced bioconversion of coal to methane compared with anaerobic digestion:Insights into differences in metabolic pathways[J]. Energy Conversion and Management,2022,259:115553.

[23] ZHAO Zhiqiang,WANG Jianfeng,LI Yang,et al. Why do DIETers like drinking:Metagenomic analysis for methane and energy metabolism during anaerobic digestion with ethanol[J]. Water Research,2020,171:115425.

[24] PRAJAPAT A L,GOGATE P R. Intensification of degradation of guar gum:Comparison of approaches based on ozone,ultraviolet and ultrasonic irradiations[J]. Chemical Engineering and Processing:Process Intensification,2015,98:165−173.

[25] HREIZ R,LATIFI M A,ROCHE N. Optimal design and operation of activated sludge processes:State–of–the–art[J]. Chemical Engineering Journal,2015,281:900−920.

[26] PASALARI H,GHOLAMI M,REZAEE A,et al. Perspectives on microbial community in anaerobic digestion with emphasis on environmental parameters:A systematic review[J]. Chemosphere,2021,270:128618.

[27] 叶建平. 中国煤层气勘探开发及其科技进步历程回顾与思考[J]. 煤田地质与勘探,2025,53(1):114−127

YE Jianping. China’s CBM exploration and production and associated technological advancements:A review and reflections[J]. Coal Geology & Exploration,2025,53(1):114−127

[28] 徐凤银,闫霞,林振盘,等. 我国煤层气高效开发关键技术研究进展与发展方向[J]. 煤田地质与勘探,2022,50(3):1−14

XU Fengyin,YAN Xia,LIN Zhenpan,et al. Research progress and development direction of key technologies for efficient coalbed methane development in China[J]. Coal Geology & Exploration,2022,50(3):1−14

[29] 张立国,李建政,班巧英,等. pH对UASB运行效能及产甲烷互营菌群的影响[J]. 哈尔滨工业大学学报,2013,45(8):44−49

ZHANG Liguo,LI Jianzheng,BAN Qiaoying,et al. Impact of pH on performance and syntrophic community of hydrogen–producing acetogens and methanogens in an UASB[J]. Journal of Harbin Institute of Technology,2013,45(8):44−49

[30] 张松,刘敏,陈滢. 酸化冲击对低pH厌氧发酵系统性能的影响[J]. 环境工程学报,2017,11(5):2646−2653

ZHANG Song,LIU Min,CHEN Ying. Effect of acidification shock on performance of anaerobic fermentation system at low pH[J]. Chinese Journal of Environmental Engineering,2017,11(5):2646−2653

[31] GASTONE F,TOSCO T,SETHI R. Green stabilization of microscale iron particles using guar gum:Bulk rheology,sedimentation rate and enzymatic degradation[J]. Journal of Colloid and Interface Science,2014,421:33−43.

[32] BOSCHEE P. Produced and flowback water recycling and reuse:Economics,limitations,and technology[J]. Oil and Gas Facilities,2014,3(1):16−21.

[33] AHMADI M,JORFI S,KUJLU R,et al. A novel salt–tolerant bacterial consortium for biodegradation of saline and recalcitrant petrochemical wastewater[J]. Journal of Environmental Management,2017,191:198−208.

[34] MA Xin，LEI Guanglun，WANG Zhihui，et al. Microbial remediation of guar–based fracturing fluid damage[C]//SPE International Conference and Exhibition on Formation Damage Control. Lafayette：Society of Petroleum Engineers，2018：SPE–189487–MS.

[35] 马鑫,雷光伦,王志惠,等. 胍胶降解菌对地层压裂液伤害的修复机制[J]. 中国石油大学学报(自然科学版),2018,42(4):100−110

MA Xin,LEI Guanglun,WANG Zhihui,et al. Remediation mechanism of guar degrading bacteria on hydraulic fracturing fluid damage[J]. Journal of China University of Petroleum (Edition of Natural Science),2018,42(4):100−110

[36] ZHANG Anlong,GAO Chuyue,CHEN Tiantian,et al. Treatment of fracturing wastewater by anaerobic granular sludge:The short–term effect of salinity and its mechanism[J]. Bioresource Technology,2022,345:126538.

[37] LIANG Jiahao,WANG Qinghong,YOZA B A,et al. Degradation of guar in an up–flow anaerobic sludge blanket reactor:Impacts of salinity on performance robustness,granulation and microbial community[J]. Chemosphere,2019,232:327−336.

[38] 彭晶. 酸性矿山废水来源β–甘露聚糖酶的挖掘和耐酸机制研究[D]. 长沙：中南大学，2023.

PENG Jing. Mining and acid tolerance mechanisms study of novel β–mannanases from acid mine drainage[D]. Changsha：Central South University，2023.

[39] LIANG Jiahao,WANG Qinghong,LI Jin,et al. Effects of anaerobic granular sludge towards the treatment of flowback water in an up–flow anaerobic sludge blanket bioreactor:Comparison between mesophilic and thermophilic conditions[J]. Bioresource Technology,2021,326:124784.

[40] 达祺安,姚传进,曲晓欢,等. 低温油气藏胍胶压裂液破胶酶的研制与性能评价[J]. 中国石油大学学报(自然科学版),2022,46(2):137−144

DA Qi’an,YAO Chuanjin,QU Xiaohuan,et al. Preparation and performance evaluation of enzyme gel breaker for guar–based fracturing fluid in low–temperature reservoirs[J]. Journal of China University of Petroleum (Edition of Natural Science),2022,46(2):137−144

[41] 宋萍. 压裂液破胶酶制取及破胶效果评价[D]. 东营：中国石油大学(华东)，2020.

SONG Ping. Study on preparation and performance of an enzyme breaker for guar–based fracturing fluid[D]. Dongying：China University of Petroleum (East China)，2020.

[42] 罗会颖. 极端嗜酸真菌Bispora sp. MEY–1胞外糖苷水解酶类的产酶分析及其相关基因的克隆与表达[D]. 北京：中国农业科学院，2008.

LUO Huiying. Secreted enzyme analysis，gene cloning and heterologous expression of glycoside hydrolases of acidophilic fungus Bispora sp. MEY–1[D]. Beijing：Chinese Academy of Agricultural Sciences，2008.