Mamo Gashaw
Biotechnology, Center for Chemistry & Chemical Engineering, Lund University, 221 00, Lund, Sweden.
Adv Biochem Eng Biotechnol. 2016;156:433-464. doi: 10.1007/10_2016_6.
Aerobic microorganisms have been sources of medicinal agents for several decades and an impressive variety of drugs have been isolated from their cultures, studied and formulated to treat or prevent diseases. On the other hand, anaerobes, which are believed to be the oldest life forms on earth and evolved remarkably diverse physiological functions, have largely been neglected as sources of bioactive compounds. However, results obtained from the limited research done so far show that anaerobes are capable of producing a range of interesting bioactive compounds that can promote human health. In fact, some of these bioactive compounds are found to be novel in their structure and/or mode of action.Anaerobes play health-promoting roles through their bioactive products as well as application of whole cells. The bioactive compounds produced by these microorganisms include antimicrobial agents and substances such as immunomodulators and vitamins. Bacteriocins produced by anaerobes have been in use as preservatives for about 40 years. Because these substances are effective at low concentrations, encounter relatively less resistance from bacteria and are safe to use, there is a growing interest in these antimicrobial agents. Moreover, several antibiotics have been reported from the cultures of anaerobes. Closthioamide and andrimid produced by Clostridium cellulolyticum and Pantoea agglomerans, respectively, are examples of novel antibiotics of anaerobe origin. The discovery of such novel bioactive compounds is expected to encourage further studies which can potentially lead to tapping of the antibiotic production potential of this fascinating group of microorganisms.Anaerobes are widely used in preparation of fermented foods and beverages. During the fermentation processes, these organisms produce a number of bioactive compounds including anticancer, antihypertensive and antioxidant substances. The well-known health promoting effect of fermented food is mostly due to these bioactive compounds. In addition to their products, whole cell anaerobes have very interesting applications for enhancing the quality of life. Probiotic anaerobes have been on the market for many years and are receiving growing acceptance as health promoters. Gut anaerobes have been used to treat patients suffering from severe Clostridium difficile infection syndromes including diarrhoea and colitis which cannot be treated by other means. Whole cell anaerobes are also studied to detect and cure cancer. In recent years, evidence is emerging that anaerobes constituting the microbiome are linked to our overall health. A dysfunctional microbiome is believed to be the cause of many diseases including cancer, allergy, infection, obesity, diabetes and several other disorders. Maintaining normal microflora is believed to alleviate some of these serious health problems. Indeed, the use of probiotics and prebiotics which favourably change the number and composition of the gut microflora is known to render a health promoting effect. Our interaction with the microbiome anaerobes is complex. In fact, not only our lives but also our identities are more closely linked to the anaerobic microbial world than we may possibly imagine. We are just at the beginning of unravelling the secret of association between the microbiome and human body, and a clear understanding of the association may bring a paradigm shift in the way we diagnose and treat diseases and disorders. This chapter highlights some of the work done on bioactive compounds and whole cell applications of the anaerobes that foster human health and improve the quality of life.
几十年来，需氧微生物一直是药物的来源，人们已从它们的培养物中分离出了种类繁多的药物，并对其进行研究和配制成用于治疗或预防疾病的药物。另一方面，厌氧菌被认为是地球上最古老的生命形式，进化出了极为多样的生理功能，但在很大程度上被忽视了作为生物活性化合物的来源。然而，目前有限的研究结果表明，厌氧菌能够产生一系列有趣的生物活性化合物，这些化合物可以促进人类健康。事实上，其中一些生物活性化合物在结构和/或作用方式上是新颖的。厌氧菌通过其生物活性产物以及全细胞的应用发挥促进健康的作用。这些微生物产生的生物活性化合物包括抗菌剂以及免疫调节剂和维生素等物质。厌氧菌产生的细菌素作为防腐剂已使用了约40年。由于这些物质在低浓度下有效，相对较少受到细菌的耐药性影响且使用安全，因此人们对这些抗菌剂的兴趣与日俱增。此外，已有报道称从厌氧菌培养物中分离出了几种抗生素。分别由溶纤维梭菌和成团泛菌产生的氯硫酰胺和安迪米德就是厌氧菌来源的新型抗生素的例子。这类新型生物活性化合物的发现有望鼓励进一步的研究，这可能会挖掘出这一迷人的微生物群体的抗生素生产潜力。
厌氧菌广泛用于发酵食品和饮料的制备。在发酵过程中，这些微生物会产生多种生物活性化合物，包括抗癌、抗高血压和抗氧化物质。发酵食品众所周知的促进健康作用主要归因于这些生物活性化合物。除了其产物外，全细胞厌氧菌在提高生活质量方面还有非常有趣的应用。益生菌厌氧菌已在市场上销售多年，并越来越被人们接受为健康促进剂。肠道厌氧菌已被用于治疗患有严重艰难梭菌感染综合征（包括腹泻和结肠炎）且无法通过其他方法治疗的患者。全细胞厌氧菌也被研究用于检测和治疗癌症。近年来，越来越多的证据表明，构成微生物群的厌氧菌与我们的整体健康有关。功能失调的微生物群被认为是包括癌症、过敏症、感染、肥胖症、糖尿病和其他几种疾病在内的许多疾病的病因。维持正常的微生物群落被认为可以缓解其中一些严重的健康问题。事实上，已知使用能有利地改变肠道微生物群落数量和组成的益生菌和益生元具有促进健康的作用。我们与微生物群厌氧菌的相互作用很复杂。实际上，不仅我们的生活，而且我们的身份都与厌氧微生物世界的联系比联系联系得比我们可能想象的更为紧密。我们才刚刚开始揭开微生物群与人体之间关联的秘密，对这种关联的清晰理解可能会给我们诊断和治疗疾病及紊乱的方式带来范式转变。本章重点介绍了一些关于厌氧菌的生物活性化合物和全细胞应用的研究工作，这些研究有助于促进人类健康并提高生活质量。
