The application of microbial strains as axenic cultures has frequently been employed in a diverse range of sectors. In the natural environment, microbes exist as multispecies and perform better than monocultures. Cell signaling and communication pathways play a key role in engineering microbial consortia, because in a consortium, the microorganisms communicate via diffusible signal molecules. Mixed microbial cultures have gained little attention due to the lack of proper knowledge about their interactions with each other. Some ideas have been proposed to deal with and study various microbes when they live together as a community, for biotechnological application purposes. In natural environments, microbes can possess unique metabolic features. Therefore, microbial consortia divide the metabolic burden among strains in the group and robustly perform pesticide degradation. Synthetic microbial consortia can perform the desired functions at naturally contaminated sites. Therefore, in this article, special attention is paid to the microbial consortia and their function in the natural environment. This review comprehensively discusses the recent applications of microbial consortia in pesticide degradation and environmental bioremediation. Moreover, the future directions of synthetic consortia have been explored. The review also explores the future perspectives and new platforms for these approaches, besides highlighting the practical understanding of the scientific information behind consortia.

Biotechnological basis of microbial consortia for the removal of pesticides from the environment.

Polyethylene terephthalate (PET) is the most widespread synthetic polyester, having been utilized in textile fibers and packaging materials for beverages and food, contributing considerably to the global solid waste stream and environmental plastic pollution. While enzymatic PET recycling and upcycling have recently emerged as viable disposal methods for a circular plastic economy, only a handful of benchmark enzymes have been thoroughly described and subjected to protein engineering for improved properties over the last 16 years. By analyzing the specific material properties of PET and the reaction mechanisms in the context of interfacial biocatalysis, this Perspective identifies several limitations in current enzymatic PET degradation approaches. Unbalanced enzyme–substrate interactions, limited thermostability, and low catalytic efficiency at elevated reaction temperatures, and inhibition caused by oligomeric degradation intermediates still hamper industrial applications that require high catalytic efficiency. To overcome these limitations, successful protein engineering studies using innovative experimental and computational approaches have been published extensively in recent years in this thriving research field and are summarized and discussed in detail here. The acquired knowledge and experience will be applied in the near future to address plastic waste contributed by other mass-produced polymer types (e.g., polyamides and polyurethanes) that should also be properly disposed by biotechnological approaches.

Mechanism-Based Design of Efficient PET Hydrolases

Advancements in polymer science and engineering have helped the scientific community to shift its attention towards the use of environmentally benign materials for reducing the environmental impact of conventional synthetic plastics. Biopolymers are environmentally benign, chemically versatile, sustainable, biocompatible, biodegradable, inherently functional, and ecofriendly materials that exhibit tremendous potential for a wide range of applications including food, electronics, agriculture, textile, biomedical, and cosmetics. This review also inspires the researchers toward more consumption of biopolymer-based composite materials as an alternative to synthetic composite materials. Herein, an overview of the latest knowledge of different natural- and synthetic-based biodegradable polymers and their fiber-reinforced composites is presented. The review discusses different degradation mechanisms of biopolymer-based composites as well as their sustainability aspects. This review also elucidates current challenges, future opportunities, and emerging applications of biopolymeric sustainable composites in numerous engineering fields. Finally, this review proposes biopolymeric sustainable materials as a propitious solution to the contemporary environmental crisis. • Use of biopolymers has emerged as a new paradigm of the ecological conservation. • Biopolymeric composites are easily degraded under the possible source of degraded environment. • Biopolymers have found their applications in biomedical, food, electronics, cosmetics and other emerging fields. • Further understanding on their mode of action through this comprehensive review will imparts knowledge. 

Biopolymeric Sustainable Materials and their Emerging Applications

Increased energy demands in today’s world have led to the exploitation of fossil resources as fuel. Fossil resources are not only on the verge of extinction but also causing environmental and economic issues. Due to these reasons, scientists have started focusing their interest on other eco-friendly processes to biofuel and recently, second-generation biorefinery is gaining much more attention. In second-generation biorefinery, the main objective is the valorization of lignocellulosic biomass cost-effectively. Therefore, many scientists started different bioprocessing techniques like Consolidated Bioprocessing (CBP) to produce ethanol by using a single or plethora of microorganisms to produce ethanol in a single process. In this review, in-depth study on CBP is assessed as well as biofuel’s socio-economic value and a brief study of biorefineries. The study not only involves innovative approaches used in CBP but their effect on society and economic aspects.

https://www.mdpi.com/2073-4395/10/11/1834/pdf

Consolidated Bioprocessing, an Innovative Strategy towards Sustainability for Biofuels Production from Crop Residues: An Overview

On the degradation of (micro)plastics: Degradation methods, influencing factors, environmental impacts.

Biodegradation and up-cycling of polyurethanes: Progress, challenges, and prospects

Consolidated bioprocessing (CBP) has been considered as a cost-effective strategy for the efficient bioconversion of lignocellulosic biomass into valuable chemicals. Microbial consortium can comple...

Consolidated Bioprocessing of Hemicellulose-Enriched Lignocellulose to Succinic Acid through a Microbial Cocultivation System

The global production of glycerol is increasing year by year since the demands of biodiesel is rising. It is benefit for high-yield succinate synthesis due to its high reducing property. A. succinogenes, a succinate-producing candidate, cannot grow on glycerol anaerobically, as it needs a terminal electron acceptor to maintain the balance of intracellular NADH and NAD+. Microbial fuel cell (MFC) has been widely used to release extra intracellular electrons. However, A. succinogenes is a non-electroactive strain which need the support of electron shuttle in MFC, and pervious research showed that acid-tolerant A. succinogenes has higher content of unsaturated fatty acids, which may be beneficial for the transmembrane transport of lipophilic electron shuttle. MFC-assisted succinate production was evaluated using neutral red as an electron shuttle to recover the glycerol utilization. First, an acid-tolerant mutant JF1315 was selected by atmospheric and room temperature plasma (ARTP) mutagenesis aiming to improve transmembrane transport of neutral red (NR). Additionally, MFC was established to increase the ratio of oxidized NR to reduced NR. By combining these two strategies, ability of JF1315 for glycerol utilization was significantly enhanced, and 23.92 g/L succinate was accumulated with a yield of 0.88 g/g from around 30 g/L initial glycerol, along with an output voltage above 300 mV. A novel MFC-assisted system was established to improve glycerol utilization by A. succinogenes for succinate and electricity production, making this system as a platform for chemicals production and electrical supply simultaneously.

/pdf/microbial-fuel-cell-assisted-utilization-of-glycerol-for-201mxqgfy7.pdf

Microbial fuel cell-assisted utilization of glycerol for succinate production by mutant of Actinobacillus succinogenes

Due to the heavy metabolic burden and low efficiency of microbial pure cultures during the biotechnological process for biochemicals production, researchers have focused on microbial cocultivation ...

Application of Cell Immobilization Technology in Microbial Cocultivation Systems for Biochemicals Production

Microbial consortia are ubiquitous in nature and exhibit several attractive features such as sophisticated metabolic capabilities and strong environmental robustness. This study aimed to decipher the metabolic and ecological characteristics of synergistic interactions in acetamiprid-degrading consortia, suggesting an optimal scheme for bioremediation of organic pollutants. The microbial consortium ACE-3 with excellent acetamiprid-degrading ability was enriched from the soil of an acetamiprid-contaminated site and characterized using high-throughput sequencing (HTS). Consortium ACE-3 was able to completely degrade 50 mg⋅L-1 acetamiprid in 144 h, and was metabolically active at a wide range of pH values (6.0-8.0) and temperatures (20-42°C). Furthermore, plausible metabolic routes of acetamiprid biodegradation by the consortium were proposed based on the identification of intermediate metabolites (Compounds I, II, III and IV). The findings indicated that the consortium ACE-3 has promising potential for the removal and detoxification of pesticides because it produces downstream metabolites (Compounds I and II) that are less toxic to mammals and insects than acetamiprid. Finally, Illumina HTS revealed that β Proteobacteria were the dominant group, accounting for 85.61% of all sequences at the class level. Among the more than 50 genera identified in consortium ACE-3, Sphingobium, Acinetobacter, Afipia, Stenotrophomonas, and Microbacterium were dominant, respectively accounting for 3.07, 10.01, 24.45, and 49.12% of the total population.

/pdf/characterization-of-acetamiprid-biodegradation-by-the-59esan5ivl.pdf

Bin Xu

Papers

Biodegradation and up-cycling of polyurethanes: Progress, challenges, and prospects

Consolidated Bioprocessing of Hemicellulose-Enriched Lignocellulose to Succinic Acid through a Microbial Cocultivation System

Microbial fuel cell-assisted utilization of glycerol for succinate production by mutant of Actinobacillus succinogenes

Application of Cell Immobilization Technology in Microbial Cocultivation Systems for Biochemicals Production

Characterization of Acetamiprid Biodegradation by the Microbial Consortium ACE-3 Enriched From Contaminated Soil.