Microbial Biotechnology最新文献

Biomineralization, the capacity to form minerals, has evolved in a great diversity of bacterial lineages as an adaptation to different environmental conditions and biological functions. Microbial biominerals often display original properties (morphology, composition, structure, association with organics) that significantly differ from those of abiotically formed counterparts, altogether defining the ‘mineral phenotype’. In principle, it should be possible to take advantage of microbial biomineralization processes to design and biomanufacture advanced mineral materials for a range of technological applications. In practice, this has rarely been done so far and only for a very limited number of biomineral types. This is mainly due to our poor understanding of the underlying molecular mechanisms controlling microbial biomineralization pathways, preventing us from developing bioengineering strategies aiming at improving biomineral properties for different applications. Another important challenge is the difficulty to upscale microbial biomineralization from the lab to industrial production. Addressing these challenges will require combining expertise from environmental microbiologists and geomicrobiologists, who have historically been working at the forefront of research on microbe–mineral interactions, alongside bioengineers and material scientists. Such interdisciplinary efforts may in the future allow the emergence of a mineral biomanufacturing industry, a critical tool towards the development more sustainable and circular bioeconomies.

Microfluidic droplets

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8616014/

This review article covers two-phase biocatalysis in microfluidic droplets. This often serves to overcome mass transport issues that can limit enzyme catalysis with water-insoluble compounds.

Two-step organic synthesis biocatalysis

https://pubs.acs.org/doi/10.1021/acs.oprd.6b00232

This study used whole-cell catalysts in a microaqueous phase within organic solvents to catalyse multiple enzymatic steps for making a pharmaceutical intermediate.

Flow biocatalysis

https://www.frontiersin.org/articles/10.3389/fctls.2023.1154452/full

This review covered new developments in flow biocatalysis during the years of 2020–2022.

Encapsulated Pseudomonas biotransformation

https://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-023-02073-7

In this report, the authors describe optimization of (S)-2-hydroxypropiophenone synthesis by free and encapsulated cells of P. putida.

Biocatalysis methods

https://www.nature.com/articles/s43586-021-00044-z

This is a broad and extensive review of biocatalysis that includes many aspects for using enzymes to synthesis commercial chemicals.

Pickering emulsions with yeast enzyme

https://pubs.acs.org/doi/10.1021/acssuschemeng.6b01776

This article describes the use of a small amount of solid particle emulsifier to make a Pickering emulsion system to catalyse reactions with Candida antarctica lipase B.

Pharma biocatalysis

https://www.almacgroup.com/knowledge/wp-content/uploads/sites/10/2021/01/API_Practical-Methods-for-Biocatalysis-and-Biotransformations-2_Article-2.pdf

This review chapter focuses on company-based biocatalysis projects.

Microbial biocatalysis

https://www.mdpi.com/journal/catalysts/special_issues/microbes_biocatal

This links to a special issue of the journal “Catalysts” that includes examples of two-phase microbial and enzyme biocatalysis.

Diene epoxidation by a Pseudomonas

https://www.sciencedirect.com/science/article/abs/pii/0141022986900761

This article highlights the production of 7,8-epoxy-1-octene by non-growing Pseudomonas putida PpG6 in two-phase catalytic reaction.

Schematic overview of DNA data storage.

Climate change has rapidly altered many ecosystems, with detrimental effects for biodiversity across the globe. In recent years, it has become increasingly apparent that the microorganisms that live in and on animals can substantially affect host health and physiology, and the structure and function of these microbial communities can be highly sensitive to environmental variables. To date, most studies have focused on the effects of increasing mean temperature on gut microbiota, yet other aspects of climate are also shifting, including temperature variation, seasonal dynamics, precipitation and the frequency of severe weather events. This array of environmental pressures might interact in complex and non-intuitive ways to impact gut microbiota and consequently alter animal fitness. Therefore, understanding the impacts of climate change on animals requires a consideration of multiple types of environmental stressors and their interactive effects on gut microbiota. Here, we present an overview of some of the major findings in research on climatic effects on microbial communities in the animal gut. Although ample evidence has now accumulated that shifts in mean temperature can have important effects on gut microbiota and their hosts, much less work has been conducted on the effects of other climatic variables and their interactions. We provide recommendations for additional research needed to mechanistically link climate change with shifts in animal gut microbiota and host fitness.

A better understanding of the genetic regulation of the biosynthesis of microbial compounds could accelerate the discovery of new biologically active molecules and facilitate their production. To this end, we have investigated the time course of genome-wide transcription in the myxobacterium Sorangium sp. So ce836 in relation to its production of natural compounds. Time-resolved RNA sequencing revealed that core biosynthesis genes from 48 biosynthetic gene clusters (BGCs; 92% of all BGCs encoded in the genome) were actively transcribed at specific time points in a batch culture. The majority (80%) of polyketide synthase and non-ribosomal peptide synthetase genes displayed distinct peaks of transcription during exponential bacterial growth. Strikingly, these bursts in BGC transcriptional activity were associated with surges in the net production rates of known natural compounds, indicating that their biosynthesis was critically regulated at the transcriptional level. In contrast, BGC read counts from single time points had limited predictive value about biosynthetic activity, since transcription levels varied >100-fold among BGCs with detected natural products. Taken together, our time-course data provide unique insights into the dynamics of natural compound biosynthesis and its regulation in a wild-type myxobacterium, challenging the commonly cited notion of preferential BGC expression under nutrient-limited conditions. The close association observed between BGC transcription and compound production warrants additional efforts to develop genetic engineering tools for boosting compound yields from myxobacterial producer strains.

In order to address the global crisis in pear productivity, there has been increased attention given to advocating for the use of organic fertilizers. As part of this effort, researchers have been investigating the microbial properties of organic fertilizers to better understand their potential impact on fruit productivity. Our research focused specifically on the impact of four different ratios of sheep manure (SM) and chemical fertilizers (CF) on pear productivity. We found that replacing CF with SM resulted in a proliferation of gammaproteobacteria, Chlamydiae, Bastocatellia and Clostridia in the soil rhizosphere, which is the region around the roots of plants where most nutrient uptake occurs. Using redundancy analysis, we were able to determine that SM was particularly effective at promoting the growth of gammaproteobacteria and clostridia, which were associated with C:N ratios around 14:1 as well as the availability of K, Fe, Zn and Cu. This combination of factors was conducive to a transition from vegetative growth to reproductive growth, resulting in an increase in pear production from 43 to 56 tons per hectare. We also discovered that Blastociella acts as a buffering system in regulating soil acidity. Taken together, our findings indicate that a combination of SM and CF can improve the abundance of beneficial bacteria in the rhizosphere, leading to an increase in pear productivity.

Microbe-based drug delivery.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895346/

This review targets microbe-based drug delivery with the goal of providing site-specific medical benefits to patients.

Synthetic microbes as drug delivery systems.

https://pubs.acs.org/doi/10.1021/sb500258b

This article examines potential developments in medicine for using microbes to diagnose disease, produce therapeutics in situ, and deliver medicines.

Microbial-fabricated nano-systems.

https://www.frontiersin.org/articles/10.3389/fchem.2021.617353/full

This is a broad treatment on the formulations of microbes with metals, polysaccharides, and other agents for making nano-scale delivery agents.

Modes of therapeutic delivery.

https://www.cell.com/trends/microbiology/fulltext/S0966-842X(22)00249-9

This review discusses bacterial therapeutics and vaccines, with a focus on those moving into clinical trials.

Bacteria and anti-cancer drugs.

https://www.sciencedirect.com/science/article/pii/S0168365920303849

This review article highlights the use of bacteria or bacterial derivatives as drug carriers for cancer therapy.

Bacterial drug delivery IP.

https://www.wipo.int/wipo_magazine/en/2014/04/article_0002.html

This interesting article in the World International Patent Organization (WIPO) magazine discusses a microbial drug patented for the treatment of gastrointestinal disorders.

Bacterial lysing systems in cancer therapy.

https://www.nature.com/articles/s41467-021-26367-9

This article deals with the use of a Salmonella-derived delivery system to induce lysis and release proteins specifically into tumour cells.

Bacteria and medical implants.

https://www.mdpi.com/2079-4983/13/4/173

This deals with bacterially responsive drug delivery for the release of antibacterial compounds at the site of implants to mitigate against infections.

Anti-microbial peptide delivery.

https://agris.fao.org/agris-search/search.do?recordID=US202000140612

Nano-scale drug delivery systems are being investigated for the delivery of bacterially produced toxins called bacteriocins.

There is much human disadvantage and unmet need in the world, including deficits in basic resources and services considered to be human rights, such as drinking water, sanitation and hygiene, healthy nutrition, access to basic healthcare, and a clean environment. Furthermore, there are substantive asymmetries in the distribution of key resources among peoples. These deficits and asymmetries can lead to local and regional crises among peoples competing for limited resources, which, in turn, can become sources of discontent and conflict. Such conflicts have the potential to escalate into regional wars and even lead to global instability. Ergo: in addition to moral and ethical imperatives to level up, to ensure that all peoples have basic resources and services essential for healthy living and to reduce inequalities, all nations have a self-interest to pursue with determination all available avenues to promote peace through reducing sources of conflicts in the world. Microorganisms and pertinent microbial technologies have unique and exceptional abilities to provide, or contribute to the provision of, basic resources and services that are lacking in many parts of the world, and thereby address key deficits that might constitute sources of conflict. However, the deployment of such technologies to this end is seriously underexploited. Here, we highlight some of the key available and emerging technologies that demand greater consideration and exploitation in endeavours to eliminate unnecessary deprivations, enable healthy lives of all and remove preventable grounds for competition over limited resources that can escalate into conflicts in the world. We exhort central actors: microbiologists, funding agencies and philanthropic organisations, politicians worldwide and international governmental and non-governmental organisations, to engage – in full partnership – with all relevant stakeholders, to ‘weaponise’ microbes and microbial technologies to fight resource deficits and asymmetries, in particular among the most vulnerable populations, and thereby create humanitarian conditions more conducive to harmony and peace.

Lactococcus lactis, a lactic acid bacterium with a typical fermentative metabolism, can also use oxygen as an extracellular electron acceptor. Here we demonstrate, for the first time, that L. lactis blocked in NAD⁺ regeneration can use the alternative electron acceptor ferricyanide to support growth. By electrochemical analysis and characterization of strains carrying mutations in the respiratory chain, we pinpoint the essential role of the NADH dehydrogenase and 2-amino-3-carboxy-1,4-naphtoquinone in extracellular electron transfer (EET) and uncover the underlying pathway systematically. Ferricyanide respiration has unexpected effects on L. lactis, e.g., we find that morphology is altered from the normal coccoid to a more rod shaped appearance, and that acid resistance is increased. Using adaptive laboratory evolution (ALE), we successfully enhance the capacity for EET. Whole-genome sequencing reveals the underlying reason for the observed enhanced EET capacity to be a late-stage blocking of menaquinone biosynthesis. The perspectives of the study are numerous, especially within food fermentation and microbiome engineering, where EET can help relieve oxidative stress, promote growth of oxygen sensitive microorganisms and play critical roles in shaping microbial communities.

The recent introduction of non-conventional yeast species as companion wine starters has prompted a growing interest in microbial interactions during wine fermentation. There is evidence of interactions through interference and exploitation competition, as well as interactions depending on physical contact. Furthermore, the results of some transcriptomic analyses suggest interspecific communication, but the molecules or biological structures involved in recognition are not well understood. In this work, we explored extracellular vesicles (EVs) as possible mediators of interspecific communication between wine yeasts. The transcriptomic response of Saccharomyces cerevisiae after 3 h of contact with a fraction enriched in EVs of Metschnikowia pulcherrima was compared with that induced by active M. pulcherrima cells. Interestingly, there is a high level of overlap between the transcriptomic profiles of yeast cells challenged by either M. pulcherrima whole cells or the EV-enriched fraction. The results indicate an upregulation of yeast metabolism in response to competing species (in line with previous results). This finding points to the presence of a signal, in the EV-enriched fraction, that can be perceived by the yeast cells as a cue for the presence of competitors, even in the absence of metabolically active cells of the other species.