{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/88243"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/88243","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Microbial community responses of an anaerobic enrichment to temperature shocks","abstract":"Anaerobic digestion (AD) accomplishes degradation of complex organics in wastewater to methane and CO2 mediated by ecological cooperation of microorganisms with different metabolic functions. Previous studies have reported that temperature fluctuation could lead to AD process instability and failure, perhaps through disruption of microbial cooperation. Nevertheless, understanding of how AD microbiota respond to temperature shock is poor. Specifically, we have yet to identify organisms vulnerable to heat shock or responsible for recovering post-shock AD activity. To systematically address these questions, a mesophilic benzoate-degrading methanogenic enrichment was exposed to different levels of temperature perturbation from 45°C to 70°C for 5 or 15 min. Perturbations over this temperature gradient revealed three types of post-shock methane production profiles: no inhibition (45 and 50°C), initial inhibition with gradual recovery (55 and 60°C), and complete inhibition (70°C). These responses were also reflected in the RNA- and DNA- based 16S rRNA gene analysis of the microbial community. The primary benzoate-degrading syntroph (Syntrophus-related population) was highly affected by heat shock temperature, and its abundance was crucial to the restoration of benzoate degradation after the perturbation. In contrast, two major methanogen populations were relatively stable regardless whether methane production was inhibited. Other bacteria showed different response patterns, indicating distinct physiological and ecological traits. For example, a Firmicutes-related population rose to >50% abundance post shock, perhaps surviving through spore formation and thriving on detritus degradation. Members of “Ca. Cloacimonetes”, Spirochaetes, Bacteroidetes and Thermotogae were also stimulated while Desulfovibrio and another Spirochaetes member was inhibited. Though the exact roles of these minor microbial populations are unknown, their ubiquity across AD suggests that they are functionally important. Overall, temperature perturbation provided ecological characterization of core microbial populations in AD and can further generate knowledge on how to deal with unexpected heat shock, a common accident, thus improve the stability and performance of AD processes.","abstract_html":"Anaerobic digestion (AD) accomplishes degradation of complex organics in wastewater to methane and CO2 mediated by ecological cooperation of microorganisms with different metabolic functions. Previous studies have reported that temperature fluctuation could lead to AD process instability and failure, perhaps through disruption of microbial cooperation. Nevertheless, understanding of how AD microbiota respond to temperature shock is poor. Specifically, we have yet to identify organisms vulnerable to heat shock or responsible for recovering post-shock AD activity. To systematically address these questions, a mesophilic benzoate-degrading methanogenic enrichment was exposed to different levels of temperature perturbation from 45°C to 70°C for 5 or 15 min. Perturbations over this temperature gradient revealed three types of post-shock methane production profiles: no inhibition (45 and 50°C), initial inhibition with gradual recovery (55 and 60°C), and complete inhibition (70°C). These responses were also reflected in the RNA- and DNA- based 16S rRNA gene analysis of the microbial community. The primary benzoate-degrading syntroph (Syntrophus-related population) was highly affected by heat shock temperature, and its abundance was crucial to the restoration of benzoate degradation after the perturbation. In contrast, two major methanogen populations were relatively stable regardless whether methane production was inhibited. Other bacteria showed different response patterns, indicating distinct physiological and ecological traits. For example, a Firmicutes-related population rose to >50% abundance post shock, perhaps surviving through spore formation and thriving on detritus degradation. Members of “Ca. Cloacimonetes”, Spirochaetes, Bacteroidetes and Thermotogae were also stimulated while Desulfovibrio and another Spirochaetes member was inhibited. Though the exact roles of these minor microbial populations are unknown, their ubiquity across AD suggests that they are functionally important. Overall, temperature perturbation provided ecological characterization of core microbial populations in AD and can further generate knowledge on how to deal with unexpected heat shock, a common accident, thus improve the stability and performance of AD processes.","abstract_has_math":false,"creators":["Mei, Ran"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Environmental Engineering in Civil Engineering","degree_department":null,"school":null,"contributors":["Liu, Wen-Tso"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-29T21:02:46Z","date_published":"2015-09-29T21:02:46Z","updated_at":"2026-07-22T22:26:31Z","subjects":["microbial community","responses","temperature shocks"],"languages":["en"],"rights":["Copyright 2015 Ran Mei"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/88243","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Liu, Wen-Tso"]},{"key":"dc:creator","label":"Author","values":["Mei, Ran"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-29T21:02:46Z","2017-09-30T09:15:18Z","2015-08","2015-05-22","2015-8"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Environmental Engineering in Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["microbial community","responses","temperature shocks"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 Ran Mei"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/88243"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Anaerobic digestion (AD) accomplishes degradation of complex organics in wastewater to methane and CO2 mediated by ecological cooperation of microorganisms with different metabolic functions. Previous studies have reported that temperature fluctuation could lead to AD process instability and failure, perhaps through disruption of microbial cooperation. Nevertheless, understanding of how AD microbiota respond to temperature shock is poor. Specifically, we have yet to identify organisms vulnerable to heat shock or responsible for recovering post-shock AD activity. To systematically address these questions, a mesophilic benzoate-degrading methanogenic enrichment was exposed to different levels of temperature perturbation from 45°C to 70°C for 5 or 15 min. Perturbations over this temperature gradient revealed three types of post-shock methane production profiles: no inhibition (45 and 50°C), initial inhibition with gradual recovery (55 and 60°C), and complete inhibition (70°C). These responses were also reflected in the RNA- and DNA- based 16S rRNA gene analysis of the microbial community. The primary benzoate-degrading syntroph (Syntrophus-related population) was highly affected by heat shock temperature, and its abundance was crucial to the restoration of benzoate degradation after the perturbation. In contrast, two major methanogen populations were relatively stable regardless whether methane production was inhibited. Other bacteria showed different response patterns, indicating distinct physiological and ecological traits. For example, a Firmicutes-related population rose to >50% abundance post shock, perhaps surviving through spore formation and thriving on detritus degradation. Members of “Ca. Cloacimonetes”, Spirochaetes, Bacteroidetes and Thermotogae were also stimulated while Desulfovibrio and another Spirochaetes member was inhibited. Though the exact roles of these minor microbial populations are unknown, their ubiquity across AD suggests that they are functionally important. Overall, temperature perturbation provided ecological characterization of core microbial populations in AD and can further generate knowledge on how to deal with unexpected heat shock, a common accident, thus improve the stability and performance of AD processes.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-08-01","The student, Ran Mei, accepted the attached license on 2015-05-21 at 17:42.","The student, Ran Mei, submitted this Thesis for approval on 2015-05-21 at 18:06.","This Thesis was approved for publication on 2015-05-22 at 16:48.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8247 on 2015-09-29 at 15:05:03","Made available in DSpace on 2015-09-29T21:02:46Z (GMT). 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Previous studies have reported that temperature fluctuation could lead to AD process instability and failure, perhaps through disruption of microbial cooperation. Nevertheless, understanding of how AD microbiota respond to temperature shock is poor. Specifically, we have yet to identify organisms vulnerable to heat shock or responsible for recovering post-shock AD activity. To systematically address these questions, a mesophilic benzoate-degrading methanogenic enrichment was exposed to different levels of temperature perturbation from 45°C to 70°C for 5 or 15 min. Perturbations over this temperature gradient revealed three types of post-shock methane production profiles: no inhibition (45 and 50°C), initial inhibition with gradual recovery (55 and 60°C), and complete inhibition (70°C). These responses were also reflected in the RNA- and DNA- based 16S rRNA gene analysis of the microbial community. The primary benzoate-degrading syntroph (Syntrophus-related population) was highly affected by heat shock temperature, and its abundance was crucial to the restoration of benzoate degradation after the perturbation. In contrast, two major methanogen populations were relatively stable regardless whether methane production was inhibited. Other bacteria showed different response patterns, indicating distinct physiological and ecological traits. For example, a Firmicutes-related population rose to >50% abundance post shock, perhaps surviving through spore formation and thriving on detritus degradation. Members of “Ca. Cloacimonetes”, Spirochaetes, Bacteroidetes and Thermotogae were also stimulated while Desulfovibrio and another Spirochaetes member was inhibited. Though the exact roles of these minor microbial populations are unknown, their ubiquity across AD suggests that they are functionally important. Overall, temperature perturbation provided ecological characterization of core microbial populations in AD and can further generate knowledge on how to deal with unexpected heat shock, a common accident, thus improve the stability and performance of AD processes.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-08-01","The student, Ran Mei, accepted the attached license on 2015-05-21 at 17:42.","The student, Ran Mei, submitted this Thesis for approval on 2015-05-21 at 18:06.","This Thesis was approved for publication on 2015-05-22 at 16:48.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8247 on 2015-09-29 at 15:05:03","Made available in DSpace on 2015-09-29T21:02:46Z (GMT). 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