Improved exopolysaccharide production from Bacillus licheniformis MS3: Optimization and structural/functional characterization

Production optimization and antioxidant potential of exopolysaccharide produced by a moderately halophilic bacterium Virgibacillus dokdonensis VITP14

This study aimed to enhance the extracellular polymeric substances (EPS) production of Virgibacillus dokdonensis VITP14 and explore its antioxidant potential. EPS and biomass production by VITP14 strain were studied under different culture parameters and media compositions using one factor at a time method. Among different nutrient sources, glucose and peptone were identified as suitable carbon and nitrogen sources. Furthermore, the maximum EPS production was observed at 5% of inoculum size, 5 g/L of NaCl, and 96 h of fermentation. Response surface methodology was employed to augment EPS production and investigate the optimal levels of nutrient sources with their interaction. The strain was observed to produce actual maximum EPS of about 26.4 g/L for finalized optimum medium containing glucose 20 g/L, peptone 10 g/L, and NaCl 50 g/L while the predicted maximum EPS was 26.5 g/L. There was a nine fold increase in EPS production after optimization study. Additionally, EPS has exhibited significant scavenging, reducing, and chelating potential (>85%) at their higher concentration. This study imparts valuable insights into optimizing moderately halophilic bacterial EPS production and evaluating its natural antioxidant properties. According to findings, V. dokdonensis VITP14 was a promising isolate that will provide significant benefits to biopolymer producing industries.

A glucomannan produced by Bacillus velezensis HY23 and its growth promoting effect on soybeans under salt stress

The Bacillus genus is widely distributed in nature, has bacteriostatic and growth-promoting activities, and has broad application potential in agriculture. An exopolysaccharide (EPS) was extracted and purified from Bacillus velezensis HY23. Structural characterisation of the EPS was performed by chemical and spectroscopic analyses. Methylation analysis showed that the EPS of HY23 was composed of mannose and glucose at a ratio of 82:18 and was identified as glucomannan. Combined with the nuclear magnetic resonance (NMR) analysis, EPS from HY23 had a backbone of →2)-α-D-Manp-(1 → and →2,6)-α-D-Manp-(1 → branched at C-6 with terminal α-(3-O-Me)-D-Manp-(1 → and →6)-α-D-Manp-(1 → residues as the side chain. A certain amount of β-D-Glcp residues were also present in backbone. Moreover, EPS significantly improved the nitrogen-fixing activity and salt resistance of soybean seedlings by regulating the antioxidant pool and expression of ion transporters. These findings indicate that EPS from B. velezensis HY23 is a potential biostimulant for enhancing plant resistance to salt stress.

Microbial- and seaweed-based biopolymers: Sources, extractions and implications for soil quality improvement and environmental sustainability - A review

Improving soil quality without creating any environmental problems is an unescapable goal of sustainable agroecosystem management, according to the United Nations 2030 Agenda for Sustainable Development. Therefore, sustainable solutions are in high demand. One of these is the use of biopolymers derived from microbes and seaweed. This paper aims to provide an overview of the sources of extraction and use of microbial (bacteria and cyanobacteria) and seaweed-based biopolymers as soil conditioners, the characteristics of biopolymer-treated soils, and their environmental concerns. A preliminary search was also carried out on the entire Scopus database on biopolymers to find out how much attention has been paid to biopolymers as biofertilizers compared to other applications of these molecules until now. Several soil quality indicators were evaluated, including soil moisture, color, structure, porosity, bulk density, temperature, aggregate stability, nutrient availability, organic matter, and microbial activity. The mechanisms involved in improving soil quality were also discussed.

Anti-Photodamage Effect of Agaricus blazei Murill Polysaccharide on UVB-Damaged HaCaT Cells

UVB radiation is known to induce photodamage to the skin, disrupt the skin barrier, elicit cutaneous inflammation, and accelerate the aging process. Agaricus blazei Murill (ABM) is an edible medicinal and nutritional fungus. One of its constituents, Agaricus blazei Murill polysaccharide (ABP), has been reported to exhibit antioxidant, anti-inflammatory, anti-tumor, and immunomodulatory effects, which suggests potential effects that protect against photodamage. In this study, a UVB-induced photodamage HaCaT model was established to investigate the potential reparative effects of ABP and its two constituents (A1 and A2). Firstly, two purified polysaccharides, A1 and A2, were obtained by DEAE-52 cellulose column chromatography, and their physical properties and chemical structures were studied. A1 and A2 exhibited a network-like microstructure, with molecular weights of 1.5 × 104 Da and 6.5 × 104 Da, respectively. The effects of A1 and A2 on cell proliferation, the mitochondrial membrane potential, and inflammatory factors were also explored. The results show that A1 and A2 significantly promoted cell proliferation, enhanced the mitochondrial membrane potential, suppressed the expression of inflammatory factors interleukin-1β (IL-1β), interleukin-8 (IL-8), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), and increased the relative content of filaggrin (FLG) and aquaporin-3 (AQP3). The down-regulated JAK-STAT signaling pathway was found to play a role in the response to photodamage. These findings underscore the potential of ABP to ameliorate UVB-induced skin damage.

Revisiting microbial exopolysaccharides: a biocompatible and sustainable polymeric material for multifaceted biomedical applications

Microbial exopolysaccharides (EPS) have gained significant attention as versatile biomolecules with multifarious applications across various sectors. This review explores the valorisation of EPS and its potential impact on diverse sectors, including food, pharmaceuticals, cosmetics, and biotechnology. EPS, secreted by microorganisms, possess unique physicochemical properties, such as high molecular weight, water solubility, and biocompatibility, making them attractive for numerous functional roles. Additionally, EPS exhibit significant bioactivity, contributing to their potential use in pharmaceuticals for drug delivery and tissue engineering applications. Moreover, the eco-friendly and sustainable nature of microbial EPS production aligns with the growing demand for environmentally conscious processes. However, challenges still exist in large-scale production, purification, and regulatory approval for commercial use. Advances in bioprocessing and microbial engineering offer promising solutions to overcome these hurdles. Stringent investigations have concluded EPS as novel sources for sustainable applications that are likely to emerge and develop, further reinforcing the significance of these biopolymers in addressing contemporary societal needs and driving innovation in various industrial sectors. Overall, the microbial EPS represents a thriving field with immense potential for meeting diverse industrial demands and advancing sustainable technologies.

Anaerobic flora, Selenomonas ruminis sp. nov., and the bacteriocinogenic Ligilactobacillus salivarius strain MP3 from crossbred-lactating goats

This study aimed to examine the distribution of anaerobic bacteria in the rumen fluid of Thai crossbred goats and to screen potential probiotic strains capable of producing antimicrobial compounds and inhibiting bacteria that cause milk fat depression. Thirty-four strains of bacteria from the rumen fluid were divided into 13 groups within 12 genera based on 16S rRNA gene sequences. The RF1-5 and RF5-12 were identified as Streptococcus luteliensis and Bacillus licheniformis, respectively, and demonstrated non-ropy exopolysaccharide. Furthermore, mPRGC5T was closely related to Selenomonas caprae JCM 33725 T (97.8% similarity) based on 16S rRNA gene sequences. It exhibited low average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values with related type strains ranging from 84.9 to 86.0%, 21.3 to 21.8%, and 73.8 to 76.1%, respectively. The genotypic and phenotypic characteristics of mPRGC5T strongly support this strain as a new species of the genus Selenomonas for which the name Selenomonas ruminis mPRGC5T was proposed. The type strain is mPRGC5T (= JCM 33724 T = KCTC 25177 T). Ligilactobacillus salivarius MP3 showed antibacterial activity against Cutibacterium acnes subsp. acnes DSM 1897 T and Kocuria rhizophila MIII. The enterolysin A cluster gene was identified in its genome. The auto-aggregation of L. salivarius MP3 was 93.6 ± 0.2%. Additionally, co-aggregation of L. salivarius MP3 with C. acnes DSM 1897 T and K. rhizophila MIII had 92.2 ± 3.4% and 87.3 ± 4.5%, respectively. The adhesion capacity of strain MP3 was 76.11 ± 2.2%. Probiogenomic analysis revealed that L. salivarius MP3 was nonhazardous to animal supplementation and included acid- and bile-tolerant ability. However, strain MP3 contained three antibiotic resistance genes. Thus, the supplementation of L. salivarius MP3 could increase the milk fat content by suppressing C. acnes DSM 1897 T with antibiotic resistance gene horizontal transfer awareness.

Development of Biological Coating from Novel Halophilic Exopolysaccharide Exerting Shelf-Life-Prolonging and Biocontrol Actions for Post-Harvest Applications

The literature presents the preserving effect of biological coatings developed from various microbial sources. However, the presented work exhibits its uniqueness in the utilization of halophilic exopolysaccharides as food coating material. Moreover, such extremophilic exopolysaccharides are more stable and economical production is possible. Consequently, the aim of the presented research was to develop a coating material from marine exopolysaccharide (EPS). The significant EPS producers having antagonistic attributes against selected phytopathogens were screened from different marine water and soil samples. TSIS01 isolate revealed the maximum antagonism well and EPS production was selected further and characterized as Bacillus tequilensis MS01 by 16S rRNA analysis. EPS production was optimized and deproteinized EPS was assessed for biophysical properties. High performance thin layer chromatography (HPTLC) analysis revealed that EPS was a heteropolymer of glucose, galactose, mannose, and glucuronic acid. Fourier transform infrared spectroscopy, X-ray diffraction, and UV-visible spectra validated the presence of determined sugars. It showed high stability at a wide range of temperatures, pH and incubation time, ≈1.63 × 106 Da molecular weight, intermediate solubility index (48.2 ± 3.12%), low water holding capacity (12.4 ± 1.93%), and pseudoplastic rheologic shear-thinning comparable to xanthan gum. It revealed antimicrobial potential against human pathogens and antioxidants as well as anti-inflammatory potential. The biocontrol assay of EPS against phytopathogens revealed the highest activity against Alternaria solani. The EPS-coated and control tomato fruits were treated with A. solani suspension to check the % disease incidence, which revealed a significant (p < 0.001) decline compared to uncoated controls. Moreover, it revealed shelf-life prolonging action on tomatoes comparable to xanthan gum and higher than chitosan. Consequently, the presented marine EPS was elucidated as a potent coating material to mitigate post-harvest losses.

Evaluation of antioxidation, regulation of glycolipid metabolism and potential as food additives of exopolysaccharide from Sporidiobolus pararoseus PFY-Z1

At present, there are relatively few studies on the production of exopolysaccharide (EPS) by yeasts. Therefore, exploring the properties of EPS produced by yeast can not only enrich the source of EPS, but also play an important role in its future application in the food field. The aim of this study was to explore the biological activities of EPS (named SPZ) from Sporidiobolus pararoseus PFY-Z1, as well as the dynamic changes in physical and chemical properties that occur during simulated gastrointestinal digestion, and the effects of SPZ on microbial metabolites during fecal fermentation in vitro. The results revealed that SPZ had good water solubility index, water-holding capacity, emulsifying ability, coagulated skim milk, antioxidant properties, hypoglycemic activities, and bile acid-binding abilities. Furthermore, the content of reducing sugars increased from 1.20 ± 0.03 to 3.34 ± 0.11 mg/mL after gastrointestinal digestion, and had little effect on antioxidant activities. Moreover, SPZ could promote the production of short-chain fatty acids during fermentation for 48 h, in particular, propionic acid and n-butyric acid increased to 1.89 ± 0.08 and 0.82 ± 0.04 mmol/L, respectively. Besides this, SPZ could inhibit LPS production. In general, this study can help us to better understand the potential bioactivities, and the changes in bio-activities of compounds after digestion of SPZ.

Statistical optimization of waste molasses-based exopolysaccharides and self-sustainable bioelectricity production for dual chamber microbial fuel cell by Bacillus piscis

BACKGROUND

The application of exopolysaccharide-producing bacteria (EPS) in dual chamber microbial fuel cells (DCMFC) is critical which can minimize the chemical oxygen demand (COD) of molasses with bioelectricity production. Hence, our study aimed to evaluate the EPS production by the novel strain Bacillus piscis by using molasses waste. Therefore, statistical modeling was used to optimize the EPS production. Its structure was characterized by UV, FTIR, NMR, and monosaccharides compositions. Eventually, to highlight B. piscis' adaptability in energy applications, bioelectricity production by this organism was studied in the BCMFC fed by an optimized molasses medium.

RESULTS

B. piscis OK324045 characterized by 16S rRNA is a potent EPS-forming organism and yielded a 6.42-fold increase upon supplementation of molasses (5%), MgSO4 (0.05%), and inoculum size (4%). The novel exopolysaccharide produced by Bacillus sp. (EPS-BP5M) was confirmed by the structural analysis. The findings indicated that the MFC's maximum close circuit voltage (CCV) was 265 mV. The strain enhanced the performance of DCMFC achieving maximum power density (PD) of 31.98 mW m-2, COD removal rate of 90.91%, and color removal of 27.68%. Furthermore, cyclic voltammetry (CV) revealed that anodic biofilms may directly transfer electrons to anodes without the use of external redox mediators. Additionally, CV measurements made at various sweep scan rates to evaluate the kinetic studies showed that the electron charge transfer was irreversible. The SEM images showed the biofilm growth distributed over the electrode's surface.

CONCLUSIONS

This study offers a novel B. piscis strain for EPS-BP5M production, COD removal, decolorization, and electricity generation of the optimized molasses medium in MFCs. The biosynthesis of EPS-BP5M by a Bacillus piscis strain and its electrochemical activity has never been documented before. The approach adopted will provide significant benefits to sugar industries by generating bioelectricity using molasses as fuel and providing a viable way to improve molasses wastewater treatment.

Exopolysaccharide from Lactococcus hircilactis CH4 and Lactobacillus delbrueckii GRIPUMSK as new therapeutics to treat biofilm pathogens, oxidative stress and human colon adenocarcinoma

Naturally occurring biopolymers like exopolysaccharides (EPS) secreted by lactic acid bacteria (LAB) has gained significant attention as they are cost effective, renewable and safe. In order to prevent the rapid increase in antibiotic resistant bacteria, the EPS of LAB offers novel approach of targeting the antibiotic resistant pathogens by limiting their effects on environment. Accordingly, in this study, the production, purification, characterization and biological properties of exopolysaccharides from Lactococcus hircilactis strain CH4 and Lactobacillus delbrueckii strain GRIPUMSK were performed. The optimization of lactic acid bacterial strains for exopolysaccharide production was done by response surface methodology and changing the carbon sources in the growth media. The carbohydrate and protein of exopolysaccharide 1 were 79.7 % and 8.7 % respectively and exopolysaccharide 2 were 75.2 % and 9.3 % respectively. When compared with the commercial emulsifier sodium dodecyl sulfate, both the exopolysaccharides have shown good emulsifying activity. Both the exopolysaccharides were linear homo-polysaccharide as determined by Fourier transform infrared spectroscopy and Nuclear magnetic resonance spectra. Scanning electron microscopy showed that the exopolysaccharides were porous and capable of holding water. The exopolysaccharides were partially crystalline as confirmed by X-ray diffraction spectra. Exopolysaccharides from L. hircilactis and L. delbrueckii exhibited significant antimicrobial activity against H. pylori, S. flexneri, S. pyogenes, E. faecalis and C. albicans. Both the exopolysaccharides revealed significant 2,2-diphenyl-1-picrylhydrazyl and hydrogen peroxide scavenging ability with the IC50 value of 100 μg/ml and 80 μg/ml respectively. Exopolysaccharides from L. hircilactis and L. delbrueckii at 100 μg/ml showed significant anticancer activity on HT-29 cells with 58.4 % and 58.7 % respectively. These findings proved that exopolysaccharides from the two selected lactic acid bacterial strains could be explored as natural bioactive carbohydrate polymer for biomedical applications.

The role of bacterial exopolysaccharides (EPS) in the synthesis of antimicrobial silver nanomaterials: A state-of-the-art review

The emergence of multi-drug resistant (MDR) pathogens poses a significant global health concern due to the failure of conventional medical treatment. As a result, the development of several metallic (Ag, Au, Zn, Ti, etc.) nanoparticles, has gained prominence as an alternative to conventional antimicrobial therapies. Among these, green-synthesized silver nanoparticles (AgNPs) have gained significant attention due to their notable efficiency and broad spectrum of antimicrobial activity. Bacterial exopolysaccharides (EPS) have recently emerged as a promising biological substrate for the green synthesis of AgNPs. EPS possess polyanionic functional groups (hydroxyl, carboxylic, sulfate, and phosphate) that effectively reduce and stabilize AgNPs. EPS-mediated AgNPs exhibit a wide range of antimicrobial activity against various pathogenic microbes, including Gram-positive and Gram-negative bacteria, as well as fungi. The extraction and purification of bacterial EPS play a vital role in obtaining high-quality and -quantity EPS for industrial applications. This study focuses on the comprehensive methodology of EPS extraction and purification, encompassing screening, fermentation optimization, pretreatment, protein elimination, precipitation, and purification. The review specifically highlights the utilization of bacterial EPS-mediated AgNPs, covering EPS extraction, the synthesis mechanism of green EPS-mediated AgNPs, their characterization, and their potential applications as antimicrobial agents against pathogens. These EPS-mediated AgNPs offer numerous advantages, including biocompatibility, biodegradability, non-toxicity, and eco-friendliness, making them a promising alternative to traditional antimicrobials and opening new avenues in nanotechnology-based approaches to combat microbial infections.

Screening of exopolysaccharide-producing Enterobacter aerogenes NJ1023 and its cadaverine biosynthesis promotion

Enterobacter aerogenes, the gram-negative bacteria belonging to the family Enterobacteriaceae, lacks the ability to synthesize chemicals. However, in this study, a strain of Enterobacter aerogenes NJ1023 screened from the soil containing petrochemicals was found to be capable of producing extracellular polysaccharides (EPSs). After purification of the polysaccharide, the chemical composition and physicochemical properties of the polysaccharide were analyzed by UV-Vis spectra, FTIR spectroscopy and GC-MS, etc. The results showed that: The molecular weight of the polysaccharide produced by this strain was only 2.7×103 Da, which was lower than that reported in other polysaccharides from the same genus. The polysaccharide produced by E. aerogenes NJ1023 mainly comprised xylose, glucose, galactose, and N-acetylglucosamine with a molar ratio of 0.27: 4.52: 1.74: 0.2, which differed from those reported from the same genus. The results demonstrated that lower incubation temperatures and shaking speeds were more favorable for EPSs synthesis, while higher incubation temperatures and shaking speeds favored cell growth. Additionally, the EPSs produced by E. aerogenes NJ1023 significantly protected the Escherichia coli cells against cadaverine stress. Overall, the discovery of EPSs produced by E. aerogenes increased the diversity of bacterial polysaccharides and broadened the potential applications of this species.

A critical review and future perspective of plastic waste recycling

Plastic waste is increasing rapidly due to urbanisation and globalization. In recent decades, plastic usage increased, and the upward trend is expected to continue. Only 9% of the 7 billion tonnes of plastic produced were recycled in India until 2022. India generates 1.5 million tonnes of plastic waste (PW) every year and ranks among top ten plastic producer countries. Large amount of waste plastics could harm environment and human health. The current manuscript provides a comprehensive approach for mechanical and chemical recycling methods. The technical facets of mechanical recycling relating to collection, sorting, grading, and general management to create plastic products with additional value have been elaborated in this study. Another sustainable methods aligned with the chemical recycling using pyrolysis, gasification, hydrocracking, IH2 (Integrated Hydropyrolysis 2), and KDV (Katalytische Drucklose Verolung) techniques have also been highlighted with the critical process parameters for the sustainable conversion of plastic waste to valuable products. The review also adheres to less carbon-intensive plastic degrading strategies that take a biomimetic approach using the microorganism based biodegradation. The informative aspects covering the limitations and effectiveness of all PW technologies and its applications towards plastic waste management (PWM) are also emphasized. The existing practices in PW policy guidelines along with its economic and ecological aspects have also been discussed.

Relationship of Gene-Structure-Antioxidant Ability of Exopolysaccharides Derived from Lactic Acid Bacteria: A Review

Polysaccharides derived from lactic acid bacteria (LAB) have widespread industrial applications owing to their excellent safety profile and numerous biological properties. The antioxidant activity of exopolysaccharides (EPS) offers defense against disease conditions caused by oxidative stress. Several genes and gene clusters are involved in the biosynthesis of EPS and the determination of their structures, which play an important role in modulating their antioxidant ability. Under conditions of oxidative stress, EPS are involved in the activation of the nonenzyme (Keap1-Nrf2-ARE) response pathway and enzyme antioxidant system. The antioxidant activity of EPS is further enhanced by the targeted alteration of their structures, as well as by chemical methods. Enzymatic modification is the most commonly used method, though physical and biomolecular methods are also frequently used. A detailed summary of the biosynthetic processes, antioxidant mechanisms, and modifications of LAB-derived EPS is presented in this paper, and their gene-structure-function relationship has also been explored.

Probiotic characteristics of Lactobacillus gasseri TF08-1: A cholesterol-lowering bacterium, isolated from human gut

Lactobacillus contribute to maintain the human healthy and use for nutritional additives as probiotics. In this study, a cholesterol-lowering bacterium, Lactobacillus gasseri TF08-1, was isolated from the feces of a healthy adolescent, and its probiotic potentials were evaluated through genomic mining and in vitro test. The assembled draft genome comprised of 1,974,590 bp and was predicted total of 1,940 CDSs. The annotation of the genome revealed that L. gasseri TF08-1 harbored abundant categories of functional genes in metabolic and information processing. Moreover, strain TF08-1 has capacity to utilize D-Glucose, Sucrose, D-Maltose, Salicin, D-Xylose, D-Cellobiose, D-Mannose, and D-Trehalose, as the carbon source. The safety assessment showed strain TF08-1 contained few antibiotic resistance genes and virulence factors and was only resistant to 2 antibiotics detected by antimicrobial susceptibility test. A high bile salt hydrolase activity was found and a cholesterol-reducing effect was determined in vitro, which the result showed a remarkable cholesterol removal capability of L. gasseri TF08-1 with an efficiency of 84.40 %. This study demonstrated that the strain showed great capability of exopolysaccharide production, and tolerance to acid and bile salt. Therefore, these results indicate that L. gasseri TF08-1 can be considered as a safe candidate for probiotic, especially its potential in biotherapeutic for metabolic diseases.

Complete genome sequence of Bacillus cereus 2-6A, a marine exopolysaccharide-producing bacterium isolated from deep-sea hydrothermal sediment of the Pacific Ocean

Bacillus cereus 2-6A, was isolated from the sediments in the hydrothermal area of the Pacific Ocean with a water depth of 2628 m. In this study, we report the whole genome sequence of strain 2-6A and analyze that to understand its metabolic capacities and biosynthesis potential of natural products. The genome of strain 2-6A consists of a circular chromosome of 5,191,018 bp with a GC content of 35.3 mol% and two plasmids of 234,719 bp and 411,441 bp, respectively. Genomic data mining reveals that strain 2-6A has several gene clusters involved in exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs) production and complex polysaccharides degradation. It also possesses a variety of genes for allowing strain 2-6A to cope with osmotic stress, oxidative stress, heat shock, cold shock and heavy metal stress, which could play a vital role in the adaptability of the strain to hydrothermal environments. Gene clusters for secondary metabolite production, such as lasso peptide and siderophore, are also predicted. Therefore, genome sequencing and data mining provide insights into the molecular mechanisms of Bacillus in adapting to hydrothermal deep ocean environments and can facilitate further experimental exploration.

Exploration of plant growth promoting traits and regulatory mechanisms of Bacillus anthracis PM21 in enhancing salt stress tolerance in maize

Bacillus species have been reported to reduce the negative effects of salt stress on plants; the involvement of Bacillus anthracis PM21 and the internal mechanisms involved in this process are unclear. The effects of PM21 inoculation on maize plants under salt stress were investigated in this study. The study aimed to assess the ability of Bacillus anthracis PM21 to endure high levels of salinity stress while preserving the concentration of plant growth regulators. The biomass, photosynthetic pigments, relative water content (RWC), antioxidants, osmoprotectants, inorganic ion contents, regulation of plant hormones and expression of antioxidants enzyme encoded genes were investigated under normal and salinity stress conditions. Bacillus anthracis PM21 produced a significant amount of 1-aminocyclopropane-1-carboxylate deaminase enzyme (ACC deaminase) and exopolysaccharides (EPS) under salt stress and normal conditions. PM21 also produced plant growth stimulants including indole acetic acid, gibberellic acid (GA3), kinetin, and siderophore under salinity stress and normal conditions. Under salt stress, PM21 inoculation markedly increased plant growth indices, stimulate antioxidant enzyme mechanisms, osmoprotectants, and chlorophyll content. The use of qRT-PCR to analyze the transcription of targeted genes indicated greater expression of antioxidant-encoded genes and inferred their possible function in salinity stress tolerance. Our findings shed light on the functions of PM21 and its regulatory mechanisms in plant salt stress tolerance, as well as the importance of PM21 in this process. This study will provide a thorough analysis of the theoretical framework for adopting PM21 in agricultural production as an eco-friendly method to enhance crop growth and yield under salinity stress.

Microbial exopolysaccharide: Sources, stress conditions, properties and application in food and environment: A comprehensive review

Microbial glucan or exopolysaccharides (EPS) have caught an eye of researchers from decades. The unique characteristics of EPS make it suitable for various food and environmental applications. This review overviews the different types of exopolysaccharides, sources, stress conditions, properties, characterization techniques and applications in food and environment. The yield and production condition of EPS is a major factor affecting the cost and its applications. Stress conditions are very important as it stimulates the microorganism for enhanced EPS production and affects its properties. As far as application is concerned specific properties of EPS such as, hydrophilicity, less oil uptake behavior, film forming ability, adsorption potential have applications in both food and environment sector. Novel and improved method of production, feed stock and right choice of microorganisms with stress conditions are critical for desired functionality and yield of the EPS.

Production and characterization of exopolysaccharides from salinity-induced Auxenochlorella protothecoides and the analysis of anti-inflammatory activity

The set scenario of this work was to investigate the production, physicochemical characteristics, and anti-inflammatory activities of exopolysaccharides from salinity-induced Auxenochlorella protothecoides. The results demonstrated that 10 ‰ salinity manipulation endowed preferable exopolysaccharide production by A. protothecoides. Under this salinity stress, ACPEPS1A and ACPEPS2A were purified from exopolysaccharide production by anion chromatography and molecular exclusion chromatography. ACPEPS1A exhibited a molecular weight (Mw) of 132 kDa and mainly consisted of galactose. ACPEPS2A was a heteropolysaccharide with an Mw of 170 kDa and the main monosaccharides of galactose and rhamnose with separate molar percents of 42.41 % and 35.29 %, respectively. FTIR, ¹H and ¹³C NMR supported that monosaccharide components of ACPEPS1A and ACPEPS2A possessed both α- and β-configuration pyranose rings. Further evidence indicated that ACPEPS1A and ACPEPS2A could effectively inhibit the inflammatory response in lipopolysaccharide (LPS) induced RAW264.7 cells by quenching inflammatory factor levels such as ROS, iNOS, TNF-α, and IL-6. The potential anti-inflammatory possibilities were that the monosaccharides of ACPEPS1A and ACPEPS2A possessed higher affinity with receptors on the macrophage surface than LPS and hampered LPS-induced inflammation. The findings of this work would favor innovative applications of exopolysaccharides from microalgae in complementary medicines or functional foods.

Biotechnological and food synthetic biology potential of platform strain: Bacillus licheniformis

Bacillus licheniformis is one of the most characteristic Gram-positive bacteria. Its unique genetic background and safety characteristics make it have important biologic applications in the food industry, including, the biosynthesis of high value-added bioproducts, probiotic functions, biological treatment of wastes derived from food production, etc. In this review, these recent advances are summarized and presented systematically for the first time. In addition, we highlight synthetic biology strategies as a potential driver of developing this strain for wider and more efficient application in the food industry. Finally, we present the current challenges faced and provide our unique perspective on relevant future research directions. In summary, this review will provide an illuminating and comprehensive perspective that will allow an in-depth understanding of B. licheniformis and promote its more effective development in the food industry.

Pestalotiopsis Diversity: Species, Dispositions, Secondary Metabolites, and Bioactivities

Pestalotiopsis species have gained attention thanks to their structurally complex and biologically active secondary metabolites. In past decades, several new secondary metabolites were isolated and identified. Their bioactivities were tested, including anticancer, antifungal, antibacterial, and nematicidal activity. Since the previous review published in 2014, new secondary metabolites were isolated and identified from Pestalotiopsis species and unidentified strains. This review gathered published articles from 2014 to 2021 and focused on 239 new secondary metabolites and their bioactivities. To date, 384 Pestalotiopsis species have been discovered in diverse ecological habitats, with the majority of them unstudied. Some may contain secondary metabolites with unique bioactivities that might benefit pharmacology.

Prospects of microbial polysaccharides-based hybrid constructs for biomimicking applications

Polysaccharides are biobased polymers obtained from renewable sources. They exhibit various interesting features including biocompatibility, biodegradability, and nontoxicity. Microbial polysaccharides are produced by several microorganisms including yeast, fungi, algae, and bacteria. Microbial polysaccharides have gained high importance in biotechnology due to their novel physiochemical characteristics and composition. Among microbial polysaccharides, xanthan, alginate, gellan, and dextran are the most commonly reported polysaccharides for the development of biomimetic materials for biomedical applications including targeted drug delivery, wound healing, and tissue engineering. Several chemical and physical cross-linking reactions are performed to increase their technological and functional properties. Owning to the broad-scale applications of microbial polysaccharides, this review aims to summarize the characteristics with different ways of physical/chemical crosslinking for polysaccharide regulation. Recently, several biopolymers have gained high importance due to their biologically active properties. This will help in the formation of bioactive nutraceuticals and functional foods. This review provides a perspective on microbial polysaccharides, with special emphasis given to applications in promising biosectors and the subsequent advancement on the discovery and development of new polysaccharides for adding new products.

Variable pH and subsequent change in pCO2 modulates the biofilm formation, synthesis of extracellular polymeric substances, and survivability of a marine bacterium Bacillus stercoris GST-03

Biofilm-forming bacteria adhere to the substrates and engage in the nutrient cycling process. However, environmental conditions may interrupt the biofilm formation ability, which ultimately may affect various biogeochemical cycles. The present study reports the effect of varying pH and subsequent change in pCO₂ on the survivability, biofilm formation, and synthesis of extracellular polymeric substances (EPS) of a biofilm-forming marine bacterium Bacillus stercoris GST-03 isolated from the Bhitarkanika mangrove ecosystem, Odisha, India. Understanding the pH-dependent alteration in EPS constituents, and associated functional groups of a marine bacterium will provide better insight into the adaptability of the bacteria in future ocean acidification scenarios. The strain was found to tolerate and form biofilm up to pH 4, with the maximum biofilm formation at pH 6. EPS yield and the synthesis of the key components of the EPS, including carbohydrate, protein, and lipid, were found maximum at pH 6. Changes in biofilm formation patterns and various topological parameters at varying pH/pCO₂ conditions were observed. A cellular chaining pattern was observed at pH 4, and maximum biofilm formation was obtained at pH 6 with biomass of 5.28582 ± 0.5372 μm³/μm² and thickness of 9.982 ± 1.5288 μm. Structural characterization of EPS showed changes in various functional groups of constituent macromolecules with varying pH. The amorphous nature of the EPS and the changes in linkages and associated functional groups (-R₂CHOR, -CH₃, and -CH₂) with pH variation was confirmed. EPS showed a two-step degradation with a maximum weight loss of 59.147% and thermal stability up to 480 °C at pH 6. The present work efficiently demonstrates the role of EPS in providing structural and functional stability to the biofilm in varying pH conditions. The findings will provide a better understanding of the adaptability of marine bacteria in the future effect of ocean acidification.

Construction of lipid-biomacromolecular compounds for loading and delivery of carotenoids: Preparation methods, structural properties, and absorption-enhancing mechanisms

Due to the unstable chemical properties and poor water solubility of carotenoids, their processing adaptation and oral bioavailability are poor, limiting their application in hydrophilic food systems. Lipid-biomacromolecular compounds can be excellent carriers for carotenoid delivery by taking full advantage of the solubilization of lipids to non-polar nutrients and the water dispersion and gastrointestinal controlled release properties of biomacromolecules. This paper reviewed the research progress of lipid-biomacromolecular compounds as encapsulation and delivery carriers of carotenoids and summarized the material selection and preparation methods for biomacromolecular compounds. By considering the interaction between the two, this paper briefly discussed the effect of these compounds on carotenoid water solubility, stability, and bioavailability, emphasizing their delivery effect on carotenoids. Finally, various challenges and future trends of lipid-biomacromolecular compounds as carotenoid delivery carriers were discussed, providing new insight into efficient loading and delivery of carotenoids.

Valorization of fruit wastes for circular bioeconomy: Current advances, challenges, and opportunities

The demands for fruits and processed products have significantly increased following the surging human population growth and rising health awareness. However, an enormous amount of fruit waste is generated during their production life-cycle due to the inedible portion and perishable nature, which become a considerable burden to the environment. Embracing the concept of "circular economy", these fruit wastes represent sustainable and renewable resources and can be integrated into biorefinery platforms for valorization into a wide range of high-value products. To fully realize the potential of fruit waste in circular bioeconomy and provide insights on future commercial-scale applications, this review presented the recycling and utilization of fruit wastes in various applications, particularly focusing on pollutant bioremediation, renewable energy and biofuel production, biosynthesis of bioactive compounds and low-cost microbial growth media. Furthermore, the challenges of efficient valorization of fruit wastes were discussed and future prospects were proposed.

Statistical Optimization of Novel Medium to Maximize the Yield of Exopolysaccharide From Lacticaseibacillus rhamnosus ZFM216 and Its Immunomodulatory Activity

The traditional media used for the fermentation of Lactobacilli always contain carbohydrate polymers, which interfere with the analysis of the exopolysaccharide (EPS) produced by the bacteria. In this investigation, a novel medium formulation that could avoid such interference was successfully developed. The beef extract, yeast extract, and peptone used in this formulation were subjected to the removal of polysaccharides before use. The factors affecting the EPS production were optimized by a single factor test, Plackett–Burman design, and Box–Behnken design. The optimum formula was ascertained as: 7.5 g L–1 yeast extract, 12.5 g L–1 beef extract, 10 g L–1 peptone, 21.23 g L–1 maltose, 5.51 g L–1 yeast nitrogen base, 2 g L–1 K2HPO4, 5 g L–1 anhydrous sodium acetate, 2 g L–1 ammonium citrate, 0.58 g L–1 MgSO4⋅7H2O, 0.25 g L–1 MnSO4⋅H2O, and 1 mL L–1 Tween 80. The initial pH of the medium was 6.5. The optimized conditions for fermentation of the strain to produce EPS were as follows: seed size 1%, culture temperature 37°C, and culture time 20 h. Optimum results showed that EPS yield was 496.64 ± 3.15 mg L–1, being 76.70% higher than that of unoptimized conditions (281.07 ± 5.90 mg L–1). The EPS was mainly comprised of glucose and guluronic acid, with a weight average molecular weight of 19.9 kDa; it was also characterized by Fourier transform infrared spectroscopy and UV analysis. EPS was found to significantly enhance the phagocytic capacity, promote the NO, TNF-α, IL-1β, and IL-6 secretion, and improve mRNA expression of cytokines in RAW 264.7 macrophages, indicating its considerable immunomodulatory activity. Western bolt and immunofluorescence results demonstrated that the EPS was able to increase p65 nuclear translocation in the macrophages, indicating that EPS enhanced immunity via the NF-κB signaling pathway. EPS investigated in this work has potential as an attractive functional food supplement candidate for the hypoimmunity population.

Physicochemical and Anti-UVB-Induced Skin Inflammatory Properties of Lacticaseibacillus paracasei Subsp. paracasei SS-01 Strain Exopolysaccharide

The exopolysaccharide secreted by Lacticaseibacillus paracasei subsp. paracasei SS-01 strain (LP-EPS) is isolated and purified from yogurt. It is a polysaccharide with a branched and multi-stranded structure, which exists in a smooth rod-like or cloud-like state, and possesses a good thermal stability and a molecular weight of 49.68 kDa (±4.436%). LP-EPS shows a high antioxidant capacity, anti-inflammatory and anti-sensitizing activity during in vitro experimental studies, with half clearance (IC50) rates of 0.449, 1.314, and 2.369 mg/mL for the ABTS, DPPH, and OH radicals, respectively, and a half inhibition rate (IC50) of hyaluronidase of 1.53 mg/mL. A cell-based assay, enzyme-linked immunosorbent assay (ELISA), and quantitative real-time fluorescence PCR (qRT-PCR) show that LP-EPS effectively treats or ameliorates the skin inflammatory responses triggered by UVB irradiation, as evidenced by a highly significant decrease in the secretion of inflammatory factors by human skin keratinocytes (HaCaT), and a highly significant downregulation of the mRNA expression of MAPK/AP-1 pathway cytokines.

Exopolysaccharides production from marine Bacillus strains and their antioxidant and bio-flocculant capacities

Microbial exopolysaccharides (EPS) have gained high scientific concern due to their exceptional physicochemical features and high industrial applicability. Owing to their biotechnological importance, the present study was designed to screen and isolate the EPS-producing Bacillus strains based on their growth potential on specific media and colony morphologies. The bacterial isolates Bacillus subtilis Bs1-01, Bacillus licheniformis Bl1-02, and Bacillus brevis Bb1-04 showed excellent EPS production due to their shortened lag phase and abundant biomass production. Shake-flask fermentation valued the maximum production yield of 50.19 ± 1.14 g/L by Bl1-02 after 72 h incubation (about 3.40 times higher than that of Bacillus thuringiensis Bt1-05). The basic component analysis revealed the improved amount of total carbohydrate, reducing sugar ends, and protein contents by Bl1-02 strain. Structural characteristics and functional groups of the EPS characterized by Fourier transform infrared spectroscopy demonstrated that all EPS were in close agreement to each other due to the presence of similar chemical bonds and functional groups. EPS from Bl1-02 strain showed stronger and more stable bio-emulsifying and hygroscopicity activities (12.23%). The crude EPS exhibited potent antioxidant properties which were examined against reducing potential (H₂O₂ scavenging) and total antioxidant tests. Among bio-flocculation activities of EPS at different concentrations, Bs1-01 strain produced EPS at a concentration of 60 mg/mL was observed to show the maximum value of 79.20%. In conclusion, the EPS from marine Bacillus strains showed excellent functional properties suggesting potential industrial applications that demand separate investigations.

Nano-engineered materials for sensing food pollutants: Technological advancements and safety issues

Food spoilage and safety are key concerns of the modern food sector. Among them, several types of polluting agents are the prime grounds of food deterioration. In this context, nanotechnology-based measures are setting new frontiers to strengthen food applications. Herein, we summarize the nanotechnological dimension of the food industry for both processing and packaging applications. Active bioseparation, smart delivery, nanoencapsulation, nutraceuticals, and nanosensors for biological detection are a few emerging topics of nanobiotechnology in the food sector. The development of functional foods is another milestone set by food nanotechnology by building the link between humans and diet. However, the establishment of optimal intake, product formulations, and delivery matrices, the discovery of beneficial compounds are a few of the key challenges that need to be addressed. Nanotechnology provides effective solutions for the aforementioned problem giving various novel nanomaterials and methodologies. Various nanodelivery systems have been designed, e.g., cochleate, liposomes, multiple emulsions, and polysaccharide-protein coacervates. However, their real applications in food sciences are very limited. This review also provides the status and outlook of nanotechnological systems for future food applications.

Performance Evaluation of Bio-Based Fractions Derived from Bacillus spp. for Potential In Situ Soil Stabilisation

Current and future research focuses on the use of renewable technologies and materials to stabilise weak soils, of varying degrees, for road construction applications. Soil stabilisation is a method of strengthening a natural soil to meet this purpose. Our interest is in the use of bio-based components, derived from microbial growth processes, that contribute to the needed desirable strength characteristics for in situ soil stabilisation. This investigation focuses on novel Bacillus-based stabilisers obtained from the vegetative and spore growth stage. In this study, eighteen bio-based components were derived from a Bacillus licheniformis fermentation and extracted into various aqueous and non-aqueous fractions for strength property assessment. The strength properties of the treated soils (i.e., dolerite and weathered granite soil) were assessed via previously developed lab-scale equipment to rapidly pre-select the best performing fractions, (i.e., compression stress, erosion, abrasion, and water absorption tests). The effect of one superior performing prototype (a) was validated at large-scale, using standard erosion and abrasion tests (i.e., whole broth at 1.8% stabiliser concentrations), and showed resistance to abrasion (3.37 ± 0.03%) (p value ≤ 0.0001) and resistance to erosion (33.20 ± 0.15%) (p value ≤ 0.001). The elemental composition and microstructure of the bio-stabilised soil was determined using energy dispersive X-ray spectroscopy and scanning electron microscopy, respectively. This evaluation formed part of the selection of the best performing Bacillus derived fractions and achieved a proof of concept for the next phase of product prototype development. This study demonstrated a novel bio-mediated approach to the overall criteria for evaluation and selection of candidate product prototype/s, for stabilisation of two varying soils, and for potential application in road construction works.

Extraction of the Bacterial Extracellular Polysaccharide FucoPol by Membrane-Based Methods: Efficiency and Impact on Biopolymer Properties

In this study, membrane-based methods were evaluated for the recovery of FucoPol, the fucose-rich exopolysaccharide (EPS) secreted by the bacterium Enterobacter A47, aiming at reducing the total water consumption and extraction time, while keeping a high product recovery, thus making the downstream procedure more sustainable and cost-effective. The optimized method involved ultrafiltration of the cell-free supernatant using a 30 kDa molecular weight cut-off (MWCO) membrane that allowed for a 37% reduction of the total water consumption and a 55% reduction of the extraction time, compared to the previously used method (diafiltration-ultrafiltration with a 100 kDa MWCO membrane). This change in the downstream procedure improved the product’s recovery (around 10% increase) and its purity, evidenced by the lower protein (8.2 wt%) and inorganic salts (4.0 wt%) contents of the samples (compared to 9.3 and 8.6 wt%, respectively, for the previously used method), without impacting FucoPol’s sugar and acyl groups composition, molecular mass distribution or thermal degradation profile. The biopolymer’s emulsion-forming and stabilizing capacity was also not affected (emulsification activity (EA) with olive oil, at a 2:3 ratio, of 98 ± 0% for all samples), while the rheological properties were improved (the zero-shear viscosity increased from 8.89 ± 0.62 Pa·s to 17.40 ± 0.04 Pa·s), which can be assigned to the higher purity degree of the extracted samples. These findings demonstrate a significant improvement in the downstream procedure raising FucoPol’s recovery, while reducing water consumption and operation time, key criteria in terms of process economic and environmental sustainability. Moreover, those changes improved the biopolymer’s rheological properties, known to significantly impact FucoPol’s utilization in cosmetic, pharmaceutical or food products.

Carrageenan-based nano-hybrid materials for the mitigation of hazardous environmental pollutants

Fast industrialization and population growth are associated with the increased release of hazardous contaminants in the environment. These hazardous substances, including pharmaceutical, biomedical, personal-care products, heavy metals, endocrine-disrupters, and colorants, pollute the ecosystem by disturbing nature's balance. Nanotechnology has paved new horizons in biochemical engineering by designing novel approaches of integrating nanoscale science with biotechnology to construct improved quality materials for target uptake of pollutants. Recently, nanostructured materials have emerged as research and development frontiers owing to their excellent properties. The tailored designing of nanohybrids constructs with physicochemical alteration enables the nano-bioadsorbent with high target specificity and efficiency. The development of eco-friendly, biodegradable, cost-efficient, and biopolymer-based nanohybrid constructs is gaining attention to remove hazardous environmental pollutants. κ-carrageenan biopolymer is frequently used with different nanomaterials to design nanohybrid bio-adsorbents to remove various contaminants. Herein, the potentialities of carrageenan-based nanohybrid constructs in environmental remediation have been summarized. Different nanostructures, e.g., silica, non-magnetic/magnetic, carbon nanotubes/nanorods, nanoclay/nanomembrane, metal organic frameworks, graphene oxide, and other nanomaterials have been described in combination with carrageenan biopolymers focusing on environmental remediation.

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

Bacillus licheniformis is a soil bacterium with many industrial applications. In addition to enzymes, platform chemicals, antibiotics and phytohormones, the species produces exopolysaccharides (EPSs) of various biological activities. This study revealed that Bulgarian isolate B. licheniformis 24 produced EPSs consisting of galactose, glucose and mannose with substrate-dependent ratio. From glucose, B. licheniformis 24 secreted EPS1, consisting of 54% galactose, 39% glucose and 7% mannose. From fructose, the strain formed EPS2, containing 51% glucose, 30% mannose and 19% galactose. Batch cultivation in flasks yielded 2.2–2.6 g/L EPS1 and 1.90–2.11 g/L EPS2. Four to five times higher yields of EPS were obtained from both substrates during batch and fed-batch processes in a fermenter at 37.8 °C, pH 6.2 and aeration 3.68 vvm. The batch process with 200 g/L of starting substrates received 9.64 g/L EPS1 and 6.29 g/L EPS2, reaching maximum values at the 33rd and 24th h, respectively. Fed-batch fermentation resulted in the highest yields, 12.61 g/L EPS1 and 7.03 g/L EPS2. In all processes, EPSs were produced only in the exponential growth phase. Both EPSs exhibited antioxidant activity, but EPS2 was much more potent in this regard, reaching 811 μM Vitamin C Equivalent Antioxidant Capacity (versus 135 μM for EPS1). EPS1 displayed antibacterial activity against a non-O1 strain of Vibrio cholerae.

Phenotypic features and analysis of genes supporting probiotic action unravel underlying perspectives of Bacillus velezensis VTX9 as a potential feed additive for swine

Purpose

To date, a total of 13 probiotic Bacillus species are considered as a Generally Recognized as Safe organism (GRAS) approved by the US Federal Food, Drug, and Cosmetic Act (FDCA), which are used for food and feed additives. However, Bacillus velezensis is not considered as a probiotic candidate in swine farming due to a lack of genetic basis of probiotic action-related traits. Therefore, the present study was undertaken to exploit the genetic basis underlying the probiotic traits of B. velezensis VTX9.

Methods

The genome sequencing of B. velezensis VTX9 was performed on a PacBio Sequel platform. The probiotic properties including biosafety, antioxidative capacity, and riboflavin and exopolysaccharide production were evaluated by using genotypic and phenotypic analysis. The secondary metabolite potentials were also predicted.

Results

Strain VTX9 isolated from swine feces proved some probiotic properties including resistance to 3 mM H2O2, 0.6 mM bile salt, low pH, and antipathogenic activity. The complete genome of B. velezensis VTX9 consists of a 3,985,800 bp chromosome that housed 3736 protein-coding genes and 5 plasmids with the size ranging from 7261 to 20,007 bp. Genome analysis revealed no functional genes encoding enterotoxins and transferable antibiotic resistance, which confirmed the safety of VTX9. A total of 82 genes involved in gastrointestinal stress tolerance were predicted, which has not been reported previously. The maximum production of riboflavin reached 769 ± 7.5 ng/ml in LB medium after 72 h, which was in agreement with the complete de novo riboflavin biosynthetic pathway exploited for the first time in the B. velezensis genome. Antagonistic activity against pathogenic bacteria was attributed to 10 secondary metabolites clusters. The presence of a large gene cluster involved in biosynthesis of exopolysaccharides underscored further the adhesion and biofilm-forming capabilities of VTX9 in swine intestines.

Conclusion

Our results revealed for the first time that B. velezensis VTX9 has the potential to be a probiotic candidate. The information provided here on the genome of B. velezensis VTX9 opens new opportunities for using B. velezensis as a feed additive for swine farming in the future.

Cellulose-deconstruction potential of nano-biocatalytic systems: A strategic drive from designing to sustainable applications of immobilized cellulases

Nanostructured materials along with an added value of polymers-based support carriers have gained high interest and considered ideal for enzyme immobilization. The recently emerged nanoscience interface in the form of nanostructured materials combined with immobilized-enzyme-based bio-catalysis has now become research and development frontiers in advance and applied bio-catalysis engineering. With the involvement of nanoscience, various polymers have been thoroughly developed and exploited to nanostructured engineer constructs as ideal support carriers/matrices. Such nanotechnologically engineered support carriers/matrix possesses unique structural, physicochemical, and functional attributes which equilibrate principal factors and strengthen the biocatalysts efficacy for multipurpose applications. In addition, nano-supported catalysts are potential alternatives that can outstrip several limitations of conventional biocatalysts, such as reduced catalytic efficacy and turnover, low mass transfer efficiency, instability during the reaction, and most importantly, partial, or complete inhibition/deactivation. In this context, engineering robust and highly efficient biocatalysts is an industrially relevant prerequisite. This review comprehensively covered various biopolymers and nanostructured materials, including silica, hybrid nanoflower, nanotubes or nanofibers, nanomembranes, graphene oxide nanoparticles, metal-oxide frameworks, and magnetic nanoparticles as robust matrices for cellulase immobilization. The work is further enriched by spotlighting applied and industrially relevant considerations of nano-immobilized cellulases. For instance, owing to the cellulose-deconstruction features of nano-immobilized cellulases, the applications like lignocellulosic biomass conversion into industrially useful products or biofuels, improved paper sheet density and pulp beat in paper and pulp industry, fruit juice clarification in food industry are evident examples of cellulases, thereof are discussed in this work.

Current Trends of Food Analysis, Safety, and Packaging

Food is a basic necessity for life, growth, survival, and maintaining a proper body function. Rising food demand leads both producers and consumers to search for alternative food sources with high nutritional value. However, food products may never be completely safe. The oxidation reaction may alter both the physicochemical and immunological properties of food products. Maillard and caramelization nonenzymatic browning reactions can play a pivotal role in food acceptance through the ways they influence quality factors such as flavor, color, texture, nutritional value, protein functionality, and digestibility. There is a multitude of adulterated foods that portray adverse risks to the human condition. To maintain food safety, the packaging material is used to preserve the quality and freshness of food products. Food safety is jeopardized by plenty of pathogens by the consumption of adulterated food resulting in multiple foodborne illnesses. Though different analytical tools are used in the analysis of food products, yet, adulterated food has repercussions for the community and is a growing issue that adversely impairs human health and well-being. Thus, pathogenic agents' rapid and effective identification is vital for food safety and security to avoid foodborne illness. This review highlights the various analytical techniques used in the analysis of food products, food structure, and quality of food along with chemical reactions in food processing. Moreover, we have also discussed the effect on health due to the consumption of adulterated food and focused on the importance of food safety, including the biodegradable packaging material.

Robust nanocarriers to engineer nanobiocatalysts for bioprocessing applications

The synergistic integration of bio-catalysis engineering with nanostructured materials, as unique multifunctional carrier matrices, has emerged as a new interface of nanobiocatalysis (NBC). NBC is an emerging innovation that offers significant considerations to expand the designing and fabrication of robust catalysts at the nanoscale with improved catalytic characteristics for multipurpose bioprocessing applications. In addition, nanostructured materials with unique structural, physical, chemical, and functional entities have manifested significant contributions in mimicking the enzyme microenvironment. A fine-tuned enzyme microenvironment with an added-value of NBC offers chemo- regio- and stereo- selectivities and specificities. Furthermore, NBC is growing rapidly and will become a powerful norm in bio-catalysis with much controlled features, such as selectivity, specificity, stability, resistivity, induce activity, reaction efficacy, multi-usability, improved mass transfer efficiency, high catalytic turnover, optimal yield, ease in recovery, and cost-effectiveness. Considering the above critics and unique structural, physicochemical, and functional attributes, herein, we present and discuss advances in NBC and its bioprocessing applications in different fields. Briefly, this review is focused on four parts, i.e., (1) NBC as a drive towards applied nanobiocatalysts (as an introduction with opportunities), (2) promising nanocarriers to develop nanobiocatalysts, (3) applications in the fields of biotransformation, biofuel production, carbohydrate hydrolysis, bio-/nanosensing, detergent formulations, and extraction and purification of value-added compounds, and (4) current challenges, concluding remarks, and future trends.

Structural elucidation and physicochemical characteristics of a novel high-molecular-weight fructan from halotolerant Bacillus sp. SCU-E108

An exopolysaccharide, EPS-B108, was isolated from the fermented broth (with a yield of 11.3 g/L) of halotolerant Bacillus sp. SCU-E108 by ethanol precipitation, anion-exchange and gel-filtration chromatography, and well characterized by means of physical, chemical and spectral techniques. Data indicated that EPS-B108 was composed solely of fructose with a high molecular weight of 3.578 × 10⁷ g/mol, and contained a β-(2 → 6)-linked d-Fruf backbone with a single β-d-Fruf at C-1 position. An irregular saccular- or cake-like shape was observed under the enlarged view. It showed no acute oral toxicity in mice, and had good thermal stability (242 °C), solubility in water (91.3%) and oil-holding capacity (1717.0%). Steady-shear flow and dynamical viscoelasticity of aqueous EPS-B108 solutions varied with the polymer concentration, shear rate and temperature, and were described by the Power-law model. Together, these findings support the further application of EPS-B108 as an alternative source of functional food additives and ingredients.

Can Sustainable Packaging Help to Reduce Food Waste? A Status Quo Focusing Plant-Derived Polymers and Additives

The promotion of sustainable packaging is part of the European Green Deal and plays a key role in the EU’s social and political strategy. One option is the use of renewable resources and biomass waste as raw materials for polymer production. Lignocellulose biomass from annual and perennial industrial crops and agricultural residues are a major source of polysaccharides, proteins, and lignin and can also be used to obtain plant-based extracts and essential oils. Therefore, these biomasses are considered as potential substitute for fossil-based resources. Here, the status quo of bio-based polymers is discussed and evaluated in terms of properties related to packaging applications such as gas and water vapor permeability as well as mechanical properties. So far, their practical use is still restricted due to lower performance in fundamental packaging functions that directly influence food quality and safety, the length of shelf life, and thus the amount of food waste. Besides bio-based polymers, this review focuses on plant extracts as active packaging agents. Incorporating extracts of herbs, flowers, trees, and their fruits is inevitable to achieve desired material properties that are capable to prolong the food shelf life. Finally, the adoption potential of packaging based on polymers from renewable resources is discussed from a bioeconomy perspective.

Purification, Structural Characteristics, and Biological Activities of Exopolysaccharide Isolated From Leuconostoc mesenteroides SN-8

In this study, a novel exopolysaccharide (EPS) was extracted from Leuconostoc mesenteroides Shen Nong's (SN)-8 which can be obtained from Dajiang. After the purification step, EPS-8-2 was obtained with molecular weights of 1.46 × 105 Da. The structural characterization of EPS indicated that the EPS belonged to the class polysaccharide, mainly composed of glucan and also contained certain mannose residues that were found to be connected by α-1,6 glycosidic bonds. Moreover, the results demonstrated that EPS displayed a significant capacity to scavenge free radical to some extent, and this anti-oxidant potential was found to be concentration dependent. The results further revealed that EPS displayed a significant inhibitory potential on the growth of HepG2 cells by promoting apoptosis and induced cell cycle arrest in G1 and G2 phases. Overall, these results suggested that EPS can be explored as a possible anti-cancer agent.

Polysaccharides-based bio-nanostructures and their potential food applications

Polysaccharides are omnipresent biomolecules that hold great potential as promising biomaterials for a myriad of applications in various biotechnological and industrial sectors. The presence of diverse functional groups renders them tailorable functionalities for preparing a multitude of novel bio-nanostructures. Further, they are biocompatible and biodegradable, hence, considered as environmentally friendly biopolymers. Application of nanotechnology in food science has shown many advantages in improving food quality and enhancing its shelf life. Recently, considerable efforts have been made to develop polysaccharide-based nanostructures for possible food applications. Therefore, it is of immense importance to explore literature on polysaccharide-based nanostructures delineating their food application potentialities. Herein, we reviewed the developments in polysaccharide-based bio-nanostructures and highlighted their potential applications in food preservation and bioactive "smart" food packaging. We categorized these bio-nanostructures into polysaccharide-based nanoparticles, nanocapsules, nanocomposites, dendrimeric nanostructures, and metallo-polysaccharide hybrids. This review demonstrates that the polysaccharides are emerging biopolymers, gaining much attention as robust biomaterials with excellent tuneable properties.

Utilization of mixed fruit waste for exopolysaccharide production by Bacillus species SRA4: medium formulation and its optimization

The main focus of this research work was to carry out the fermentative production of EPS with mixed fruit waste as substrate. The medium formulation studied by sequential addition of medium components and replacement of sugar with mixed fruit waste. Amongst the six species of Bacillus studied, Bacillus species SRA4 produced EPS in range of 3.0-17.9 g/L, which was highest amongst all the species selected for the study. Thus for further optimization, the response surface methodology was used making use of Bacillus species SRA4. EPS production enhanced to 23.75 g/L. In 10 L shake flask and fermenter scale-up study was carried out. In the study, 10 L flask showed the highest EPS production of 17.95 g/L in 120 h, whereas in 10 L fermenter, it was as high as 25.1 g/L that too in 72 h only. The optimization study resulted in 1.76-fold increase in EPS production with nearly 48 h reduction in EPS production time as compared to initial production procedure. Replacement of sucrose with fruit waste extract made the process environmentally friendly; omission of l-cystine and use of 50% reduced amount of sodium acetate in the medium lowered the production cost of EPS. This method also solved the fruit waste disposal problem.

Bio-based active food packaging materials: Sustainable alternative to conventional petrochemical-based packaging materials

In food industry, a growing concern is the use of suitable packaging material (i.e., biodegradable coatings and films) with enhanced thermal, mechanical and barrier characteristics to prevent from contamination and loss of foodstuff. Biobased polymer resources can be used for the development of biodegradable bioplastics. To achieve this goal, biopolymers should be economic, renewable and abundantly available. Bioplastic packaging materials based on renewable biomass could be used as sustainable alternative to petrochemically-originated plastic materials. This review summarizes the recent advancements in biopolymer-based coatings and films for active food packaging applications. Microbial polymers (PHA and PLA), wood-based polymers (cellulose, hemicellulose, starch & lignin), and protein-based polymers (gelatin, keratin, wheat gluten, soy protein and whey protein isolates) were among the materials most widely exploited for the development of smart packaging films. These biopolymers are able to synthesize coatings and films with good barrier properties against food borne pathogens and the transport of gases. Biobased reinforcements e.g., plant essential oils and natural additives to bioplastic films improve oxygen barrier, antibacterial and antifungal properties. To induce the desired functionality the simultaneous utilization of different synthetic and biobased polymers in the form of composites/blends is also an emerging area of research. Nanoscale reinforcements into bioplastic packaging have also been reported to improve packaging characteristics ultimately increasing food shelf life. The development of bioplastic/biocomposite and nanobiocomposites exhibits high potential to replace nonbiodegradable materials with characteristics comparable to fossil-based plastics, additionally, giving biodegradable and compostable characteristics. The idea of utilization of renewable biomass and the implications of biotechnology can firstly reduce the burden from fossil-resources, while secondly promoting biobased economy.