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Recent advancements in cancer biology, microbiology, and bioengineering have spurred the development of engineered live biotherapeutics for targeted cancer therapy. In particular, natural tumor-targeting and probiotic bacteria have been engineered for controlled and sustained delivery of anticancer agents into the tumor microenvironment (TME). Here, we review the latest advancements in the development of engineered bacteria for cancer therapy and additional engineering strategies to potentiate the delivery of therapeutic payloads. We also explore the use of combination therapies comprising both engineered bacteria and conventional anticancer therapies for addressing intratumor heterogeneity. Finally, we discuss prospects for the development and clinical translation of engineered bacteria for cancer prevention and treatment., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Lack of pathogen specificity in antimicrobial therapy causes non-discriminant microbial cell killing that disrupts the microflora present. As a result, potentially helpful microbial cells are killed along with the pathogen, altering the biodiversity and dynamic interactions within the population. Moreover, the unwarranted exposure of antibiotics to microbes increases the likelihood of developing resistance and perpetuates the emergence of multidrug resistance. Synthetic biology offers an alternative solution where specificity can be conferred to reduce the non-specific, non-targeted activity of currently available antibiotics, and instead provides targeted therapy against specific pathogens and minimising collateral damage to the host's inherent microbiota. With a greater understanding of the microbiome and the available genetic engineering tools for microbial cells, it is possible to devise antimicrobial strategies for novel antimicrobial therapy that are able to precisely and selectively remove infectious pathogens. Herein, we review the strategies developed by unlocking some of the natural mechanisms used by the microbes and how these may be utilised in targeted antimicrobial therapy, with the promise of reducing the current global bane of multidrug antimicrobial resistance.

The recently discovered roles of human microbiome in health and diseases have inspired research efforts across many disciplines to engineer microbiome for health benefits. In this review, we highlight recent progress in human microbiome research and how modifications to the microbiome could result in implications to human health. Furthermore, we discuss the application of a 'design-build-test' framework to expedite microbiome engineering efforts by reviewing current literature on three key aspects: design principles to engineer the human microbiome, methods to engineer microbiome with desired functions, and analytical techniques to examine complex microbiome samples., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The advent of sequencing technology has endowed us with the capacity to study microbes constituting the human commensal community that were previously non-culturable. Much of the initial works have concentrated on the bacterial flora constituting the gut microbiome, since specimens are readily accessible in health and disease. Less, however, is understood of the "silent population"-the fungal species, also known as the mycobiome. Living in symbiosis with bacteria as commensals in our body, it is perceivable that the mycobiome exerts an inadvertent influence on the microbiome. We review here the recent knowledge gained from study of the interaction between the mycobiome and microbiome in health and disease susceptibility, immunity, and consequences from antimicrobial treatment.

The discovery of antimicrobial drugs and their subsequent use has offered an effective treatment option for bacterial infections, reducing morbidity and mortality over the past 60 years. However, the indiscriminate use of antimicrobials in the clinical, community and agricultural settings has resulted in selection for multidrug-resistant bacteria, which has led to the prediction of possible re-entrance to the pre-antibiotic era. The situation is further exacerbated by significantly reduced antimicrobial drug discovery efforts by large pharmaceutical companies, resulting in a steady decline in the number of new antimicrobial agents brought to the market in the past several decades. Consequently, there is a pressing need for new antimicrobial therapies that can be readily designed and implemented. Recently, it has become clear that the administration of broad-spectrum antibiotics can lead to collateral damage to the human commensal microbiota, which plays several key roles in host health. Advances in genetic engineering have opened the possibility of reprogramming commensal bacteria that are in symbiotic existence throughout the human body to implement antimicrobial drugs with high versatility and efficacy against pathogenic bacteria. In this review, we discuss recent advances and potentialities of engineered bacteria in providing a novel antimicrobial strategy against antibiotic resistance., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Microbial metabolic engineering has been extensively studied for valuable chemicals synthesis, generating numerous laboratory-scale successes, and has demonstrated its potential to serve as a platform that enables large-scale manufacturing of many chemicals that are currently derived via chemical synthesis. However, the commercialization potential of microbial chemical production frequently suffers from low productivity and yields, where one key limiting factor is the inherently low tolerance of host cells against toxic compounds that are present and/or generated during biological processing. Consequently, various microbial engineering strategies have been devised to endow producer microbes with tolerance phenotypes that would be required for economically viable production of the desired chemicals. In this review, we discuss key microbial engineering strategies, devised primarily based on rational and evolutionary methodologies, that have been effective in improving cellular tolerance against fermentation inhibitors, metabolic intermediates, and valuable end-products derived from lignocellulose bioprocessing., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

LsGRP1 is a defense-related gene differentially expressed in lily leaves in response to pathogen attack. The difficulty in the expression of LsGRP1 in Escherichia coli suggested the presence of antimicrobial activity in LsGRP1. To evaluate the antimicrobial trait of LsGRP1, three LsGRP1-derived peptides were chemically synthesized; namely LsGRP1(N) (N-terminal region without the signal peptide), LsGRP1(G) (glycine-rich region), and LsGRP1(C) (C-terminal cysteine-rich region). LsGRP1(C) was proposed to be a potential antimicrobial agent according to its broad-spectrum and effective antimicrobial activity. LsGRP1(C) displayed inhibition effects on bacterial and fungal growth, possibly by altering the integrity of the cell membrane, as indicated by scanning electron microscopy and SYTOX Green staining assays. Additionally, LsGRP1(C) induced programmed cell death-like phenomenon in the tested fungal species as indicated by 2',7'-dichlorodihydrofluorescein diacetate and 4',6'-diamidino-2-phenylindole assays. Further immunofluorescence staining showed that LsGRP1(C) was located at the fungal cell surface. According to these observations, we concluded that LsGRP1(C) originated from the plant defense-related protein LsGRP1 would play a role as an antimicrobial peptide and have a potential for practical use.

Hydrogels made from epsilon-poly-l-lysine-graft-methacrylamide (EPL-MA) have been found to have impressive wide spectrum antimicrobial activity against both bacteria (specifically Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Staphylococcus aureus) and fungi (specifically Candida albicans and Fusarium solani). The EPL-MA hydrogel also possesses in vitro biocompatibility and EPL-MA solution is relatively non-hemolytic: the concentration needed for onset of human red blood cell (hRBC) hemolysis is 12,500 μg/mL so that the selectivity for the pathogenic microorganisms over hRBCs is 230-1560. Further, EPL-MA hydrogel can be conveniently ultraviolet-immobilized onto plasma-treated plastic surfaces to form thin highly adherent antimicrobial hydrogel coatings for medical devices and implants., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Agar plates with a polycyclic aromatic hydrocarbon (PAH) layer have been used to screen for microorganisms that degrade PAHs, leaving clear zones around colonies; however, there are several problems with previous methods such as undesired contamination in the fume hood and difficulty in controlling the amount of PAH on the plates. In this study, we developed a modified screening method to address the drawbacks encountered with previous screening methods. A uniform white layer of PAHs was generated by spreading PAHs dissolved in volatile solvents over a surface of solidified agar medium, followed by the evaporation of the solvents. An inoculation was then performed by spreading a molten agar medium containing microbial samples over the solidified agar medium with a PAH layer. Subsequently, the white PAH layer migrated to the surface of the molten agar medium. This essential modification enabled us not only to solve problems of the previous screening methods but also to prepare an agar plate with a PAH layer without a complicated experimental scheme in the anaerobic chamber. After solidification of the molten agar medium and incubation of the plates, clear zones were successfully detected around colonies with aerobic and anaerobic PAH-degrading microbial cultures.

Among various renewable and sustainable energy sources being explored, biobutanol has been recognized as one of the promising alternatives for biofuels due to its attractive physical and chemical properties. Various inventions have been reported for the biological production of butanol, maintaining its competitiveness in efficiency, economy, and production scale. This article reviews such patented inventions and relevant research achievements to the microbial strains and fermentation processes for the enhanced production of biobutanol. We also discuss current challenges for strain improvement based on recent developments.

SDS and Triton X-100 added at their critical micelle concentrations (CMCs), increased phenanthrene solubility in the presence of sediments and inhibited phenanthrene biodegradation. Triton X-100 caused more inhibition than SDS. 16S rDNA analyses revealed that both surfactants changed the microbial communities of phenanthrene-degrading cultures. Further, after the surfactant additions, parts of the microbial populations were not detected and methane production decreased. Surfactant applications, necessary to achieve actual CMCs, alter microbial community structure and diminish methanogenic activity under anaerobic conditions. We propose that this change may be related to the inhibitory effects of SDS and Triton X-100 on phenanthrene biodegradation under methanogenic conditions.