Novel Perspectives on Food-Based Natural Antimicrobials: A Review of Recent Findings Published since 2020.

Various fruit and vegetable wastes, particularly peels, seeds, pulp, and unprocessed residues from the food industry, are abundant sources of antioxidants and essential antimicrobial agents. These valuable bioactive compounds recovered from the food industry have a great application in food, agriculture, medicine, and pharmacology. Food-derived natural antimicrobials offer advantages such as diminishing microbial loads and prolonging the shelf life of food products particularly prone to microbial spoilage. They not only enrich the foods with antioxidants but also help prevent microbial contamination, thereby prolonging their shelf life. Similarly, incorporating these natural antimicrobials into food packaging products extends the shelf life of meat products. Moreover, in agricultural practices, these natural antimicrobials act as eco-friendly pesticides, eliminating phytopathogenic microbes responsible for causing plant diseases. In medicine and pharmacology, they are being explored as potential therapeutic agents. This review article is based on current studies conducted in the last four years, evaluating the effectiveness of food-based natural antimicrobials in food, agriculture, medicine, and pharmacology.

Evaluation of in vitro digestibility of Aspergillus oryzae fungal biomass grown on organic residue derived-VFAs as a promising ruminant feed supplement.

BACKGROUND: As demand for high quality animal feed continues to raise, it becomes increasingly important to minimize the environmental impact of feed production. An appealing sustainable approach to provide feed fractions is to use organic residues from agro-food industry. In this regard, volatile fatty acids (VFAs) such as acetic, propionic and butyric acids, derived from bioconversion of organic residues can be used as precursors for production of microbial protein with ruminant feed inclusion potential. This study aims to investigate the in vitro digestibility of the Aspergillus oryzae edible fungal biomass cultivated on VFAs-derived from anaerobic digestion of residues. The produced fungal protein biomass, along with hay clover silage and rapeseed meal were subjected to various in vitro assays using two-stage Tilley and Terry (TT), gas, and bag methods to evaluate and compare its digestibility for application in ruminant feed. RESULTS: The produced fungal biomass contained a higher crude protein (CP) (41%-49%) and rather similar neutral detergent fiber (NDF) (41%-56%) compared to rapeseed meal. The rumen in vitro dry matter digestibility (IVDMD) of the fungal biomass in the TT method ranged from 82% to 88% (statistically similar to that of the gas method (72% to 85%)). The IVDMD of fungal biomass were up to 26% and 40% greater than that of hay clover silage and rapeseed meal, respectively. The type of substrate and bag method had pronounced effect on the fermentation products (ammonium-N (NH4+-N), total gas and VFAs). Fungal biomass digestion resulted in the highest release of NH4+-N (340-540 mg/L) and the ratio of acetate to propionate ratio (3.5) among subjected substrates. CONCLUSION: The results indicate that gas method can be used as a reliable predictor for IVDMD as well as fermentation products. Furthermore, the high IVDMD and fermentation product observed for Aspergillus oryzae fungal biomass digestion, suggest that the supplementation of fungal biomass will contribute to improving the rumen digestion by providing necessary nitrogen and energy to the ruminant and microbiota.

Effects of fungal based bioactive compounds on human health: Review paper.

Since the first years of history, microbial fermentation products such as bread, wine, yogurt and vinegar have always been noteworthy regarding their nutritional and health effects. Similarly, mushrooms have been a valuable food product in point of both nutrition and medicine due to their rich chemical components. Alternatively, filamentous fungi, which can be easier to produce, play an active role in the synthesis of some bioactive compounds, which are also important for health, as well as being rich in protein content. Therefore, this review presents some important bioactive compounds (bioactive peptides, chitin/chitosan, ß-glucan, gamma-aminobutyric acid, L-carnitine, ergosterol and fructooligosaccharides) synthesized by fungal strains and their health benefits. In addition, potential probiotic- and prebiotic fungi were researched to determine their effects on gut microbiota. The current uses of fungal based bioactive compounds for cancer treatment were also discussed. The use of fungal strains in the food industry, especially to develop innovative food production, has been seen as promising microorganisms in obtaining healthy and nutritious food.

Fungal-based bioactive compounds have various health benefits.Prebiotic fungi play an active role in the regulation of gut microbiota.Anti-tumor effective fungal components will contribute to alternative medicine.Beta-glucan and chitin are the most promising fungal metabolites for cancer treatment.

Filamentous fungi for sustainable vegan food production systems within a circular economy: Present status and future prospects.

Filamentous fungi serve as potential candidates in the production of different value-added products. In the context of food, there are several advantages of using filamentous fungi for food. Among the main advantages is that the fungal biomass used food not only meets basic nutritional requirements but that it is also rich in protein, low in fat, and free of cholesterol. This speaks to the potential of filamentous fungi in the production of food that can substitute animal-derived protein sources such as meat. Moreover, life-cycle analyses and techno-economic analyses reveal that fungal proteins perform better than animal-derived proteins in terms of land use efficiency as well as global warming. The present article provides an overview of the potential of filamentous fungi as a source of food and food supplements. The commercialization potential as well as social, legal and safety issues of fungi-based food products are discussed.

Valorization of tropical fruits waste for production of commercial biorefinery products - A review.

Tropical fruit wastes (TFW) are considered as the major source of food and nutrition in the topical countries. In the recent years, modernization of agriculture has increased the tropical fruit production. Higher fruit production led to an increasing abundance in the tropical fruit waste. In general, the tropical fruit waste has no economic value and ends up in landfill. But in recent years it was observed that the tropical fruit waste can be valorized to produce value-added products ranging from compost, phytochemicals, and food products to biofuels. The tropical fruit waste has great potential to produce useful products in tropical areas. This review literature is an endeavor to understand the major tropical fruit wastes and their composition. The review presents a detailed investigation on tropical fruit waste composition, its conversion potential, role of microbes in waste valorization, production of commercially valuable products and future perspectives in waste valorization.

Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives.

For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature.

Agro waste as a potential carbon feedstock for poly-3-hydroxy alkanoates production: Commercialization potential and technical hurdles.

The enormous production and widespread applications of non -biodegradable plastics lead to their accumulation and toxicity to animals and humans. The issue can be addressed by the development of eco-friendly strategies for the production of biopolymers by utilization of waste residues like agro residues. This will address two societal issues - waste management and the development of an eco-friendly biopolymer, poly-3-hydroxy alkanoates (PHAs). Strategies adopted for utilization of agro-residues, challenges and future perspectives are discussed in detail in this comprehensive review. The possibility of PHA properties improvements can be increased by preparation of blends.

Organic waste recycling for carbon smart circular bioeconomy and sustainable development: A review.

The development of sustainable and low carbon impact processes for a suitable management of waste and by-products coming from different factors of the industrial value chain like agricultural, forestry and food processing industries. Implementing this will helps to avoid the negative environmental impact and global warming. The application of the circular bioeconomy (CB) and the circular economic models have been shown to be a great opportunity for facing the waste and by-products issues by bringing sustainable processing systems which allow to the value chains be more responsible and resilient. In addition, biorefinery approach coupled to CB context could offer different solution and insights to conquer the current challenges related to decrease the fossil fuel dependency as well as increase efficiency of resource recovery and processing cost of the industrial residues. It is worth to remark the important role that the biotechnological processes such as fermentative, digestive and enzymatic conversions play for an effective waste management and carbon neutrality.

Myco-biorefinery approaches for food waste valorization: Present status and future prospects.

Increases in population and urbanization leads to generation of a large amount of food waste (FW) and its effective waste management is a major concern. But putrescible nature and high moisture content is a major limiting factor for cost effective FW valorization. Bioconversion of FW for the production of value added products is an eco-friendly and economically viable strategy for addressing these issues. Targeting on production of multiple products will solve these issues to greater extent. This article provides an overview of bioconversion of FW to different value added products.

Improvement in desulfurization of dibenzothiophene and dibenzothiophene sulfone by Paenibacillus strains using immobilization or nanoparticle coating.

AIMS: Biodesulfurization of fossil fuels is a promising technology for deep desulfurization. Previously, we have shown that Paenibacillus strains 32O-W and 32O-Y can desulfurize dibenzothiophene (DBT) and DBT sulfone (DBTS) effectively. In this work, improvements in DBT and DBTS desulfurization by these strains were investigated through immobilization and nanoparticle coating of cells. METHODS AND RESULTS: Paenibacillus strains 32O-W and 32O-Y immobilized in alginate gel beads or coated with Fe3 O4 magnetite nanoparticles were grown at various concentrations (0.1-2 mmol l-1 ) of DBT or DBTS for 96 h. The production of 2-hydroxybiphenyl (2-HBP) from the 4S pathway biotransformation of DBT or DBTS was measured. The highest amounts of 2-HBP production occurred at concentrations of 0.1 and 0.5 mmol l-1 . Compared to planktonic cultures maximum 2-HBP production increased by 54% for DBT and 90% for DBTS desulfurization with immobilized strains, and 44% for DBT and 66% for DBTS desulfurization by nanoparticle-coated strains. CONCLUSIONS: Nanoparticle-coated and immobilized cells may be of use in efforts to increase the efficiency of biodesulfurization. SIGNIFICANCE AND IMPACT OF THE STUDY: Alginate immobilization or nanoparticle coating of bacterial cells may be useful approaches for the enhancement of biodesulfurization for eventual use on an industrial scale.

Potential use of olive oil mill wastewater for bacterial cellulose production.

In this study, olive oil mill wastewater (OOMW), an important waste in the Mediterranean basin, was evaluated to produce bacterial cellulose (BC). For this purpose, the effects of different ratios of OOMW fractions (25-100%) and some additional nutrients (yeast extract, peptone and Hestrin-Schramm medium (HS) components) on BC productions were investigated. Unsupplemented OOMW medium (75% and 100%) yielded as much as BC obtained in HS medium (0.65 g/L), while enrichment of OOMW medium (%100) with yeast extract (5 g/L) and peptone (5 g/L) increased the amount of BC by 5.5 times, reaching to 5.33 g/L. In addition, produced BCs were characterized by FT-IR, TGA, XRD and SEM analyses. BC from OOMW medium (100% OOMW with supplementation) has a high thermal decomposition temperature (316.8°C), whereas it has lower crystallinity index (57%). According to the FT-IR analysis, it was observed that the components of OOMW might be absorbed by BCs. Thus, higher yield productions of BCs from OOMW media compared to BC obtained from HS medium indicate that olive oil industry wastes can be integrated into BC production for industrial applications.

Microbiological insights into anaerobic digestion for biogas, hydrogen or volatile fatty acids (VFAs): a review.

In the past decades, considerable attention has been directed toward anaerobic digestion (AD), which is an effective biological process for converting diverse organic wastes into biogas, volatile fatty acids (VFAs), biohydrogen, etc. The microbial bioprocessing takes part during AD is of substantial significance, and one of the crucial approaches for the deep and adequate understanding and manipulating it toward different products is process microbiology. Due to highly complexity of AD microbiome, it is critically important to study the involved microorganisms in AD. In recent years, in addition to traditional methods, novel molecular techniques and meta-omics approaches have been developed which provide accurate details about microbial communities involved AD. Better understanding of process microbiomes could guide us in identifying and controlling various factors in both improving the AD process and diverting metabolic pathway toward production of selective bio-products. This review covers various platforms of AD process that results in different final products from microbiological point of view. The review also highlights distinctive interactions occurring among microbial communities. Furthermore, assessment of these communities existing in the anaerobic digesters is discussed to provide more insights into their structure, dynamics, and metabolic pathways. Moreover, the important factors affecting microbial communities in each platform of AD are highlighted. Finally, the review provides some recent applications of AD for the production of novel bio-products and deals with challenges and future perspectives of AD.

Recent trends and developments on integrated biochemical conversion process for valorization of dairy waste to value added bioproducts: A review.

In this review article, discuss the many ways utilized by the dairy sector to treat pollutants, emphasizing their influence on the quality and efficiency with which contamination is removed. It focuses on biotechnology possibilities for valorizing dairy waste in particular. The findings revealed that dairy waste may be treated using physicochemical, biological, and biotechnological techniques. Notably, this article highlighted the possibility of dairy waste being used as a feedstock not only for the generation of biogas, bioethanol, biohydrogen, microbial fuel cells, lactic acid, and fumaric acid via microbial technology but also for the production of biooil and biochar by pyrolysis. In addition, this article critically evaluates the many treatment techniques available for recovering energy and materials from dairy waste, their combinations, and implementation prospects. Valorization of dairy waste streams presents an opportunity to extend the dairy industry's presence in the fermented functional beverage sector.

Potential utilization of dairy industries by-products and wastes through microbial processes: A critical review.

The dairy industry generates excessive amounts of waste and by-products while it gives a wide range of dairy products. Alternative biotechnological uses of these wastes need to be determined to aerobic and anaerobic treatment systems due to their high chemical oxygen demand (COD) levels and rich nutrient (lactose, protein and fat) contents. This work presents a critical review on the fermentation-engineering aspects based on defining the effective use of dairy effluents in the production of various microbial products such as biofuel, enzyme, organic acid, polymer, biomass production, etc. In addition to microbial processes, techno-economic analyses to the integration of some microbial products into the biorefinery and feasibility of the related processes have been presented. Overall, the inclusion of dairy wastes into the designed microbial processes seems also promising for commercial approaches. Especially the digestion of dairy wastes with cow manure and/or different substrates will provide a positive net present value (NPV) and a payback period (PBP) less than 10 years to the plant in terms of biogas production.

Production and beneficial impact of biochar for environmental application: A comprehensive review.

This review focuses on a holistic view of biochar, production from feedstock's, engineering production strategies, its applications and future prospects. This article reveals a systematic emphasis on the continuation and development of biochar and its production methods such as Physical engineering, chemical and bio-engineering techniques. In addition, biochar alternatives such as nutrient formations and surface area made it a promising cheap source of carbon-based products such as anaerobic digestion, gasification, and pyrolysis, commercially available wastewater treatment, carbons, energy storage, microbial fuel cell electrodes, and super-capacitors repair have been reviewed. This paper also covers the knowledge blanks of strategies and ideas for the future in the field of engineering biochar production techniques and application as well as expand the technology used in the circular bio-economy.

Resource recovery and biorefinery potential of apple orchard waste in the circular bioeconomy.

In this review investigate the apple orchard waste (AOW) is potential organic resources to produce multi-product and there sustainable interventions with biorefineries approaches to assesses the apple farm industrial bioeconomy. The thermochemical and biological processes like anaerobic digestion, composting and , etc., that generate distinctive products like bio-chemicals, biofuels, biofertilizers, animal feed and biomaterial, etc can be employed for AOW valorization. Integrating these processes can enhanced the yield and resource recovery sustainably. Thus, employing biorefinery approaches with allied different methods can link to the progression of circular bioeconomy. This review article mainly focused on the different biological processes and thermochemical that can be occupied for the production of waste to-energy and multi-bio-product in a series of reaction based on sustainability. Therefore, the biorefinery for AOW move towards identification of the serious of the reaction with each individual thermochemical and biological processes for the conversion of one-dimensional providences to circular bioeconomy.

Bioprocessing strategies to increase the protein fraction of Rhizopus oryzae biomass using fish industry sidestreams.

The sidestreams produced during fish processing end in a separation tank where the resulting fractions follow biogas production or wastewater treatment. These streams can alternatively be used for production of protein-rich fungal biomass for e.g. fish feed applications, a product in increasing demand. These streams and upper streams originated during fish processing were used in this study for production of biomass using the edible filamentous fungus Rhizopus oryzae. The COD of the streams varied between 11 and 54 kg/m3 and, after fungal conversion of organic matter into protein-rich biomass and separation, a reduction of 34-69% was achieved. The stream origin had an effect on the final production and composition of the fungal biomass: 480 kg of biomass containing 33% protein per ton of COD were produced after cultivation in the separation tank streams, while 220 kg of biomass containing 62% protein per ton of COD were produced in upper sidestreams with lower amounts of suspended solids. Changing the initial pH (6.1-6.5) to 5.0 had a negative influence on the amount of biomass produced while medium supplementation had no influence. Thus, fish processing sidestreams can be diverted from biogas production and wastewater treatment to the production of protein-rich biomass for feed applications.

In-situ wrapping of tin oxide nanoparticles by bacterial cellulose derived carbon nanofibers and its application as freestanding interlayer in lithium sulfide based lithium-sulfur batteries.

Lithium-Sulfur (Li-S) batteries are mostly known for their high energy density and cost-effectiveness. However, their intrinsic problems hinder their implementation into the marketplace. The most pronounced problems are the parasitic reactions which occur between lithium polysulfides species and lithium metal anode, the volume expansion of sulfur (80%) at the end of discharge and the safety issues which are linked with the use of lithium metal. Herein this work, two approaches are applied to prevent these effects; one approach is the use of Li2S as cathode material, instead of starting from sulfur powder, both to circumvent the volume expansion of sulfur taking place during discharge and to enable lithium-free anodes cell assembling (i.e. Si-Li2S or Sn-Li2S cell configurations). Second approach deals with the lithium anode protection by SnO2 containing freestanding pyrolyzed bacterial cellulose interlayers located between anode and cathode electrodes. Since bacterial celluloses are formed in the presence of SnO2 nanoparticles, the resulting structure enables intimate contact between carbon and SnO2 nanoparticles. By employing Li2S cathode and freestanding interlayer concurrently, 468 mAh g-1 discharge capacity is obtained at C/10 current density over 100 cycles.

Repeated batch fermentation of immobilized E. coli expressing Vitreoscilla hemoglobin for long-term use.

This study describes an efficient and reusable process for ethanol production from medium containing whey powder, using alginate immobilized ethanologenic E. coli strains either expressing (TS3) or not expressing (FBR5) Vitreoscilla hemoglobin. Reuseabilities of the FBR5 and TS3 strains were investigated regarding their ethanol production capacities over the course of 15 successive 96-h batch fermentations. The ethanol production was fairly stable over the entire duration of the experiment, with strain TS3 maintaining a substantial advantage over strain FBR5. Storage of both strains in 2 different solutions for up to 60 d resulted in only a modest loss of ethanol production, with strain TS3 consistently outperforming strain FBR5 by a substantial amount. Strains stored for 15 or 30 d maintained their abilities to produce ethanol without dimunition over the course of 8 successive batch fermentations; again strain TS3 maintained a substantial advantage over strain FBR5 throughout the entire experiment. Thus, immobilization is a useful strategy to maintain the advantage in ethanol productivity afforded by expression of Vitreoscilla hemoglobin over long periods of time and large numbers of repeated batch fermentations, including, as in this case, using media with food processing wastes as the carbon source.

Effective ethanol production from whey powder through immobilized E. coli expressing Vitreoscilla hemoglobin.

Ethanol production from whey powder was investigated by using free as well as alginate immobilized E. coli and E. coli expressing Vitreoscilla hemoglobin (VHb) in both shake flask and fermenter cultures. Media with varying levels of whey (lactose contents of 3%, 5%, 8% or 15%) and yeast extract (0.3% or 0.5%) were evaluated with fermentation times of 48-96 h. Immobilization and VHb expression resulted in higher ethanol production with all media; the increases ranged from 2% to 89% for immobilization and from 2% to 182% for VHb expression. It was determined that growth medium containing 8% lactose with 0.5% yeast extract yielded the highest ethanol production for free or immobilized strains, with or without VHb expression, in both shake flask and fermenter cultures. Immobilization with alginate was found to be a promising process for ethanol production by VHb-expressing ethanologenic E. coli.