Microbial Biotechnology最新文献

Root caries is a subtype of dental caries that predominantly impacts older adults. The occurrence and progression of root caries are associated with the homeostasis of dental plaque biofilm, and microbial synergistic and antagonistic interactions in the biofilm play a significant role in maintaining the oral microecological balance. The objective of the current study was to investigate the role of Veillonella parvula in the microbial interactions and the pathogenesis of root caries. The analysis of clinical samples from patients with/without root caries revealed that Veillonella and V. parvula were abundant in the saliva of patients with root caries. More importantly, a significantly increased colonization of V. parvula was observed in root carious lesions. Further in vitro biofilm and animal study showed that V. parvula colonization increased the abundance and virulence of Streptococcus mutans and Candida albicans, leading to the formation of a polymicrobial biofilm with enhanced anti-stress capacity and cariogenicity, consequently exacerbating the severity of carious lesions. Our results indicate the critical role of V. parvula infection in the occurrence of root caries, providing a new insight for the etiological investigation and prevention of root caries.

Nanoscience, a pivotal field spanning multiple industries, including healthcare, focuses on nanomaterials characterized by their dimensions. These materials are synthesized through conventional chemical and physical methods, often involving costly and energy-intensive processes. Alternatively, biogenic synthesis using bacteria, fungi, or plant extracts offers a potentially sustainable and non-toxic approach for producing metal-based nanoparticles (NP). This eco-friendly synthesis approach not only reduces environmental impact but also enhances features of NP production due to the unique biochemistry of the biological systems. Recent advancements have shown that along with chemically synthesized NPs, biogenic NPs possess significant antimicrobial properties. The inherent biochemistry of bacteria enables the efficient conversion of metal salts into NPs through reduction processes, which are further stabilized by biomolecular capping layers that improve biocompatibility and functional properties. This mini review explores the use of bacteria to produce NPs with antimicrobial activities. Microbial technologies to produce NP antimicrobials have considerable potential to help address the antimicrobial resistance crisis, thus addressing critical health issues aligned with the United Nations Sustainability Goal #3 of good health and well-being.

The latest assessment of progress towards the Sustainable Development Goals (SDGs) has identified major obstacles, such as climate change, global instability and pandemics, which threaten efforts to achieve the SDGs even by 2050. Urgent action is needed, particularly to reduce poverty, hunger and climate change. In this context, microalgae are emerging as a promising solution, particularly in the context of food security and environmental sustainability. As versatile organisms, microalgae offer nutritional benefits such as high-quality proteins and essential fatty acids, and can be cultivated in non-arable areas, reducing competition for resources and improving the sustainability of food systems. The role of microalgae also includes other applications in aquaculture, where they serve as sustainable alternatives to animal feed, and in agriculture, where they act as biofertilizers and biostimulants. These microorganisms also play a key role in interventions on degraded land, stabilizing soils, improving hydrological function and increasing nutrient and carbon availability. Microalgae therefore support several SDGs by promoting sustainable agricultural practices and contributing to land restoration and carbon sequestration efforts. The integration of microalgae in these areas is essential to mitigate environmental impacts and improve global food security, highlighting the need for increased research and development, as well as public and political support, to exploit their full potential to advance the SDGs.

Microbial metabolism has been deeply studied over decades and it is considered to be understood to a great extent. Annotated genome sequences of many microbial species have contributed a lot to generating biochemical knowledge on metabolism. However, researchers still discover novel pathways, unforeseen reactions or unexpected metabolites which contradict to the expected canon of biochemical reactions in living organisms. Here, we highlight a few examples of such non-canonical pathways, how they were found, and what their importance in microbial biotechnology may be. The predictive power of metabolic modelling, well-founded on biochemical knowledge and genomic information is discussed in the light of both discovery of yet unknown existing metabolic routes and the prediction of others, new to Nature.

In the last two decades, new discoveries from microbiome research have changed our understanding of human health. It became evident that daily habits and lifestyle choices shape the human microbiome and ultimately determine health or disease. Therefore, we developed ‘Tiny Biome Tales’ (https://microbiome.gamelabgraz.at/), a science pedagogy video game designed like a scientific review based exclusively on peer-reviewed articles, to teach about the influence of lifestyle choices on the human microbiome during pregnancy, early and adult life, and related health consequences. Despite the scientific character, it can be played by a broad audience. Here, we also present a scientific assessment and showed that playing the game significantly contributed to knowledge gain. The innovative style of the ‘gamified review’ represents an ideal platform to disseminate future findings from microbiome research by updating existing and adding new scenes to the game.

Recently, there has been growing interest in biopreparations that intensify the decomposition of crop residues. These preparations can promote nutrient cycling and soil fertility, ultimately supporting healthy plant growth and increasing agricultural productivity. However, the development and commercialization of biopreparations poses unique challenges. Producers of biopreparations struggle to develop highly effective preparations, which then face regulatory hurdles and must win market acceptance. This literature review provides up-to-date data on microbial preparations available commercially on the European market, along with information on current relevant regulations. Challenges for the development and commercialization of new biopreparations are also discussed. The development and commercialization of biopreparations require a comprehensive approach that addresses the complex interplay of microbial and environmental factors. The need for more specific regulations on biopreparations for decomposing crop residues, clearer instructions on their use, and further research on the overall impact of biopreparations on the soil metabolome and optimal conditions for their application were indicated. Moreover, manufacturers should prioritize the development of high-quality products that meet the needs of farmers and address concerns about environmental impact and public acceptance.

Cyanobacteria are important targets for biotechnological applications due to their ability to grow in a wide variety of environments, rapid growth rates, and tractable genetic systems. They and their bioproducts can be used as bioplastics, biofertilizers, and in carbon capture and produce important secondary metabolites that can be used as pharmaceuticals. However, the photosynthetic process in cyanobacteria can be limited by a wide variety of environmental factors such as light intensity and wavelength, exposure to UV light, nutrient limitation, temperature, and salinity. Carefully considering these limitations, modifying the environment, and/or selecting cyanobacterial species will allow cyanobacteria to be used in biotechnological applications.

The human gut microbiota influences its host via multiple molecular pathways, including immune system interactions, the provision of nutrients and regulation of host physiology. Dietary fibre plays a crucial role in maintaining a healthy microbiota as its primary nutrient and energy source. Industrialisation has led to a massive decrease of habitual fibre intake in recent times, and fibre intakes across the world are below the national recommendations. This goes hand in hand with other factors in industrialised societies that may negatively affect the gut microbiota, such as medication and increased hygiene. Non-communicable diseases are on the rise in urbanised societies and the optimisation of dietary fibre intake can help to improve global health and prevent disease. Early life interventions shape the developing microbiota to counteract malnutrition, both in the context of industrialised nations with an overabundance of cheap, highly processed foods, as well as in Low- and Middle-Income Countries (LMICs). Adequate fibre intake should, however, be maintained across the life course to promote health. Here we will discuss the current state of dietary fibre research in the global context and consider different intervention approaches.

Arguably, the greatest threat to bacteria is phages. It is often assumed that those bacteria that escape phage infection have mutated or utilized phage-defence systems; however, another possibility is that a subpopulation forms the dormant persister state in a manner similar to that demonstrated for bacterial cells undergoing nutritive, oxidative, and antibiotic stress. Persister cells do not undergo mutation and survive lethal conditions by ceasing growth transiently. Slower growth and dormancy play a key physiological role as they allow host phage defence systems more time to clear the phage infection. Here, we investigated how bacteria survive lytic phage infection by isolating surviving cells from the plaques of T2, T4, and lambda (cI mutant) virulent phages and sequencing their genomes. We found that bacteria in plaques can escape phage attack both by mutation (i.e. become resistant) and without mutation (i.e. become persistent). Specifically, whereas T4-resistant and lambda-resistant bacteria with over a 100,000-fold less sensitivity were isolated from plaques with obvious genetic mutations (e.g. causing mucoidy), cells were also found after T2 infection that undergo no significant mutation, retain wild-type phage sensitivity, and survive lethal doses of antibiotics. Corroborating this, adding T2 phage to persister cells resulted in 137,000-fold more survival compared to that of addition to exponentially growing cells. Furthermore, our results seem general in that phage treatments with Klebsiella pneumonia and Pseudomonas aeruginosa also generated persister cells. Hence, along with resistant strains, bacteria also form persister cells during phage infection.

In the 21st century, the world is facing persistent global problems that have led to 193 countries to agree on the 17 Sustainable Development Goals (SDGs). The United Nations introduced these goals in 2015 to find solutions that could help end poverty, promote prosperity and protect the planet (United Nations, 2016a). In this brief perspective, we will discuss the potential role of Streptomyces in achieving those SDGs, focusing it in the current strategies applied for discovering novel compounds and in some of the problems that must be faced (Figure 1).

Members of the genus Streptomyces are filamentous Gram-positive bacteria belonging to the phylum Actinobacteria. They are ubiquitous microorganisms mainly found in soil but they can also inhabit other niches like seawater or deserts, or living associated with other organisms (Sivalingam et al., 2019). Streptomyces is mainly known for its ability to produce a wide array of bioactive secondary metabolites, which have several interesting applications in different fields (Alam et al., 2022; Demain & Sanchez, 2009; Donald et al., 2022).

One of the problems that most concern the United Nations is the existence of a growing demand for food in today's world (Food security information network, 2023). In this context, Streptomyces could play a relevant role in achieving SDG 2 (zero hunger, improved nutrition and sustainable agriculture) and SDG 1 (end poverty). Streptomyces produces several metabolites with significant commercial relevance in enhancing the nutritional value of human food and animal feed, such as vitamins like cobalamin (Rex et al., 2022). Additionally, there is an increasing need for enzymes in the global market (Grand View Research, 2023). Streptomyces due to its wide metabolic potential is used for the sustainable biotechnological production of a broad assortment of enzymes such as proteases, xylanases, amylases, lipases, keratinases, cellulases, dextranases and chitinases among others (Fernandes de Souza et al., 2022; Kumar et al., 2020). These enzymes have applications in several fields, and advantages not only in terms of energy consumption, stability, substrate specificity, purity or reaction efficiency but also in ecological and waste generation, thus contributing to the achievement of sustainable industrialization and innovation (SDG 9) and promoting responsible production and consumption (SDG 12). An example of enzymes with ecological applications is the degradation of lignocellulose and dye decolourization by detergent-stable peroxidases and laccases (Cuebas-Irizarry & Grunden, 2024). These enzymes can be potentially used to treat wastewater resulting from human activities like textile and paper industries, which cause environmental pollution and wastes that affect life below