title: Transcriptional regulation and adaptation to a high-fiber environment in Bacillus subtilis HH2 isolated from feces of the giant panda.
abstract: In the giant panda, adaptation to a high-fiber environment is a first step for the adequate functioning of intestinal bacteria, as the high cellulose content of the gut due to the panda's vegetarian appetite results in a harsh environment. As an excellent producer of several enzymes and vitamins, Bacillus subtilis imparts various advantages to animals. In our previous study, we determined that several strains of B. subtilis isolated from pandas exhibited good cellulose decomposition ability, and we hypothesized that this bacterial species can survive in and adapt well to a high-fiber environment. To evaluate this hypothesis, we employed RNA-Seq technology to analyze the differentially expressed genes of the selected strain B. subtilis HH2, which demonstrates significant cellulose hydrolysis of different carbon sources (cellulose and glucose). In addition, we used bioinformatics software and resources to analyze the functions and pathways of differentially expressed genes. Interestingly, comparison of the cellulose and glucose groups revealed that the up-regulated genes were involved in amino acid and lipid metabolism or transmembrane transport, both of which are involved in cellulose utilization. Conversely, the down-regulated genes were involved in non-essential functions for bacterial life, such as toxin and bacteriocin secretion, possibly to conserve energy for environmental adaptation. The results indicate that B. subtilis HH2 triggered a series of adaptive mechanisms at the transcriptional level, which suggests that this bacterium could act as a probiotic for pandas fed a high-fiber diet, despite the fact that cellulose is not a very suitable carbon source for this bacterial species. In this study, we present a model to understand the dynamic organization of and interactions between various functional and regulatory networks for unicellular organisms in a high-fiber environment.
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Ziyao
authors: Z
authors: Zhou
authors: Chengdu Center for Animal Disease Prevention and Control, Chengdu, 610041, PR China.
authors: Xiaoxiao
authors: X
authors: Zhou
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Jin
authors: J
authors: Li
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Zhijun
authors: Z
authors: Zhong
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Wei
authors: W
authors: Li
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Xuehan
authors: X
authors: Liu
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Furui
authors: F
authors: Liu
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Huaiyi
authors: H
authors: Su
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Yongjiu
authors: Y
authors: Luo
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Wuyang
authors: W
authors: Gu
authors: Ya'an Bifengxia Base, China Conservation and Research Center for the Giant Panda, Ya'an, 625007, PR China.
authors: Chengdong
authors: C
authors: Wang
authors: Ya'an Bifengxia Base, China Conservation and Research Center for the Giant Panda, Ya'an, 625007, PR China.
authors: Hemin
authors: H
authors: Zhang
authors: Ya'an Bifengxia Base, China Conservation and Research Center for the Giant Panda, Ya'an, 625007, PR China.
authors: Desheng
authors: D
authors: Li
authors: Ya'an Bifengxia Base, China Conservation and Research Center for the Giant Panda, Ya'an, 625007, PR China.
authors: Tingmei
authors: T
authors: He
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Hualin
authors: H
authors: Fu
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Suizhong
authors: S
authors: Cao
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Jinjiang
authors: J
authors: Shi
authors: The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
authors: Guangneng
authors: G
authors: Peng
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001412:Bacillus subtilis / Q000302:isolation & purification / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D004043:Dietary Fiber; D004734:Energy Metabolism / Q000235:genetics; D005243:Feces / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D017423:Sequence Analysis, RNA; D013171:Spores, Bacterial / Q000502:physiology; D001503:Ursidae / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D004043:Dietary Fiber; D002244:Carbon; D002482:Cellulose