Bee-collected pollen (BCP) and bee bread (BB) are honey bee products known for their beneficial biological properties. The main goal of this study was to investigate BB microbiota and its contribution to bioactivity exerted by BB. The microbiota of BB samples collected at different maturation stages was investigated via culture-independent (Next Generation Sequencing, NGS) and culture-dependent methods. Microbial communities dynamically fluctuate during BB maturation, ending in a stable microbial community structure in mature BB. Bee bread bacterial isolates were tested for phenotypes and genes implicated in the production and secretion of enzymes as well as antibacterial activity. Out of 309 bacterial isolates, 41 secreted hemicellulases, 13 cellulases, 39 amylases, 132 proteinases, 85 Coomassie brilliant blue G or R dye-degrading enzymes and 72 Malachite Green dye-degrading enzymes. Furthermore, out of 309 bacterial isolates, 42 exhibited antibacterial activity against Staphylococcus aureus, 34 against Pseudomonas aeruginosa, 47 against Salmonella enterica ser. Typhimurium and 43 against Klebsiella pneumoniae. Artificially fermented samples exerted higher antibacterial activity compared to fresh BCP, strongly indicating that BB microbiota contribute to BB antibacterial activity. Our findings suggest that BB microbiota is an underexplored source of novel antimicrobial agents and enzymes that could lead to new applications in medicine and the food industry.

Enzymatic pretreatment is an effective method which can improve the anaerobic digestion (AD) efficiency of household food waste (HFW). As an alternative to expensive commercial enzymes, mixed enzymes (MEs) produced in situ from HFW by solid-state fermentation (SSF) can greatly promote the hydrolysis rate of HFW and achieve advanced anaerobic digestion (AAD) economically sustainable. In this paper, strategies for improving the efficiency of the enzyme-production process and the abundance of MEs are briefly discussed, including SSF, fungal co-cultivation, and stepwise fermentation. The feasibility of using HFW as an applicable substrate for producing MEs (amylase, protease, and lignocellulose-degrading enzymes) and its potential advantages in HFW anaerobic digestion are comprehensively illustrated. Based on the findings, an integrated AAD process of HFW pretreated with MEs produced in situ was proposed to maximise bioenergy recovery. The mass balance results showed that the total volatile solids removal rate could reach 98.56%. Moreover, the net energy output could reach 2168.62 MJ/t HFW, which is 9.79% higher than that without in situ-produced MEs and pretreatment. Finally, perspectives for further study are presented.

Whey protein hydrolysates are recognized for their substantial functional and biological properties. Their high digestibility and amino acid composition make them a valuable ingredient to hydrolyzed whey infant formulas, enhancing both product functionality and nutritional values for infant growth. It is important to understand the functional and biological properties of whey protein hydrolysates for their applications in infant formula systems. This review explored preparation methods of whey protein hydrolysates for infant formula-based applications. The effects of whey protein hydrolysate on the physicochemical and biological properties of hydrolyzed whey infant formulas were summarized. The influences of whey protein hydrolysates on the functional and nutritional properties of formulas from manufacturing to infant consumption were discussed. Whey protein hydrolysates are crucial components in the preparation of infant formula, tailored to meet the functional and nutritional demands of the product. The selection of enzyme types and hydrolysis parameters is decisive for obtaining \"optimal\" whey protein hydrolysates that match the intended characteristics. \"Optimal\" whey protein hydrolysates offer diverse functionalities, including solubility, emulsification and production stability to hydrolyzed whey infant formulas during manufacturing processes and formulations. They simultaneously promote protein digestibility, infant growth and other potential health benefits, including reduced allergenic potential, as supported by in vitro, in vivo and clinical trials. Overall, the precise selection of enzymes and hydrolysis parameters in the production of whey protein hydrolysates is crucial in achieving the desired characteristics and functional benefits for hydrolyzed whey infant formulas, making them critical in the development of infant nutrition products.

Fish are the most edible protein source worldwide and generate several remnants such as scales, viscera, head, bone, and skin. Fish wastes are not disposed of properly, which adversely affects the environment, especially the water bodies where fish processing industries dispose of their waste. Fish waste mainly contains nitrogen, oil, fat, salts, heavy metals, and organic compounds, which increase the biological oxygen demand and chemical oxygen demand. Fish waste can degrade in various ways, such as physicochemical or by enzymatic action, but using microbes is an environmentally friendly approach that can provide valuable compounds such as products such as collagen, chitin, minerals, and fish protein concentrates. This review is designed to focus on the suitability of microbes as tools for fish waste degradation and the production of certain associated. This study also provides insight into the production of other compounds such as protease, chitinase, and chitin applicability of these products. After processing, fish waste as a microbial growth media for enzyme production since microorganisms synthesize enzymes such as proteases, protein hydrolysates, lipids, and chitinase, which have broader applications in the pharmaceutical, cosmetic, biomedical material, and food processing industries.

The genus Acrophialophora is a thermotolerant fungus, which is widely distributed in temperate and tropical zones. This fungus is classified in Ascomycota and belongs to the Chaetomiaceae family and the genera of Parathielavia, Pseudothielavia and Hyalosphaerella are closely related to Acrophialophora. For this genus have been reported 28 species so far, which two species of Acrophialophora jodhpurensis and Acrophialophora teleoafricana produce only sexual phase and other species produce asexual form. Therefore, producing both sexual and asexual forms were not reported by any species. Many applications were reported by some species in agriculture, pharmacy and industry. Production of enzymes, antimicrobial metabolites and plant growth-promoting factors were reported by some species. The species of A. nainiana is used in the industries of textile, fruit juice, pulp and paper due to extracellular enzyme production. Also, other species produce extracellular enzymes that can be used in various industries. The species Acrophialophora are used in the composting industry due to the production of various enzymes and to be thermotolerant. In addition, some species were isolated from hostile environmental conditions. Therefore has been suggested that it can be used for mycoremediation. Also, antimicrobial metabolites of Acrophialophora have been reported to be effective against human and plant pathogens. In contrast to the beneficial effects described, the Acrophialophora pathogenicity has been rarely reported. Two species A. fusispora and A. levis are opportunistic fungi and have been reported as pathogens in humans, animals and plants. Currently, the development and applications of Acrophialophora species have increased more than past. To our knowledge, there is no report with comprehensive information on the species of Acrophialophora, which include their disadvantage and beneficial effects, particularly in agriculture. Therefore, it seems necessary to pay more in-depth attention to the application of this genus as a beneficial fungus in agriculture, pharmaceutical and industry. This review is focused on the history, phylogeny, morphology, valuable roles of Acrophialophora and pathogenicity.

Recently, interest in the study of microorganisms growing under extreme conditions, particularly halophiles, has increased due to their potential use in industrial processes. Halophiles are the class of microorganisms that grow optimally at high NaCl concentrations and are capable of producing halophilic enzymes capable of catalyzing reactions under harsh conditions. So far, fungi are the least studied halophilic microorganisms, even though they have been shown to counteract these extreme conditions by producing secondary metabolites with very interesting properties. This review highlights mechanisms that allow halophilic fungi to adapt high salinity and the specificity of their enzymes to a spectrum of action in industrial and environmental applications. The peculiarities of these enzymes justify the urgent need to apply green alternative compounds in industries.

The discovery of formate dehydrogenase (Me-FDH1) from Methylorubrum extorquens has provided an avenue for sustainable CO2 fixation and utilization. However, the mass production of Me-FDH1 is challenging due to the presence of its unique tungsto-bis-metalopterin guanine dinucleotide (W-bis-MGD) cofactor, limiting its practical applications. In this study, C. necator H16 is proposed as a host for the large-scale production of Me-FDH1, utilizing fructose as a carbon source and its inherent machinery for cofactor synthesis. In a minimal salt medium, C. necator H16 could produce active Me-FDH1, which exhibited a specific activity of 80 to 100 U/mg for CO2 conversion to formate. In fed batch bioreactor experiments, approximately 50 g CDW/L (cell dry weight/L) and 10,000 U/L Me-FDH1 were achieved within 50 h. This study highlights C. necator H16 as the recombinant host for Me-FDH1, paving the way for the future development of efficient mass-production methods for this crucial enzyme.

Integrated bioprocessing strategies can facilitate ethanol production from both cellulose and hemicellulose fractions of lignocellulosic biomass. Consolidated bioprocessing (CBP) is an approach that combines enzyme production, biomass hydrolysis and sugar fermentation in a single step. However, technologies that propose the use of microorganisms together with solid biomass present the difficulty of the recovery and reuse of the biocatalyst, which can be overcome by cell immobilization. In this regard, this work applied immobilized cells of AC14 yeast, a recombinant yeast that secretes 7 hydrolytic enzymes, in the CBP process in a successful proof-of-concept for the enzyme access to the substrate polymers. The most appropriate cell load for CBP under the conditions studied with immobilized cells was selected among three optical densities (OD) 10, 55 and 100. These experiments were performed with free cells to ensure that the results were not biased by mass limitations effects. OD 10 achieved 100% of the sugar consumption and the higher specific production of enzymes, being selected for further studies. Diffusional effects were observed with immobilized cells under static conditions. However, mass transfer limitations were mitigated under agitation, with an 18.5% increase in substrate consumption rate (from 2.7 to 3.5 g/L/h), reaching the same substrate uptake rates as free cells. In addition, immobilized cells achieved 100% hydrolysis and consumption of all substrates offered within only 12 h. Overall, this is the first report of a successful application of immobilized yeast cells in CBP processes for bioethanol production, a promising technology that can be extended to other biorefinery bioproducts.

Malassezia is a major component of the skin microbiome, a lipophilic symbiotic organism of the mammalian skin, which can switch to opportunistic pathogens triggering multiple dermatological disorders in humans and animals. This phenomenon is favored by endogenous and exogenous host predisposing factors, which may switch Malassezia from a commensal to a pathogenic phenotype.
This review summarizes and discusses the most recent literature on the pathogenesis of Malassezia yeasts, which ultimately results in skin disorders with different clinical presentation. A literature search of Malassezia pathogenesis was performed via PubMed and Google scholar (up to May 2023), using the following keywords: Pathogenesis and Malassezia;host risk factors and Malassezia, Malassezia and skin disorders; Malassezia and virulence factors: Malassezia and metabolite production; Immunology and Malassezia.
Malassezia yeasts can maintain skin homeostasis being part of the cutaneous mycobiota; however, when the environmental or host conditions change, these yeasts are endowed with a remarkable plasticity and adaptation by modifying their metabolism and thus contributing to the appearance or aggravation of human and animal skin disorders.

(1) Background: This study summarizes the findings of two studies investigating the inhibitory effects of Pseudomonas aeruginosa strains from clinical and environmental sources against gram-positive and gram-negative bacteria and fungi. The studies also analyzed the correlation between enzyme production and inhibitory effects to gain insights into the antimicrobial capabilities of P. aeruginosa strains; (2) Methods: Both studies employed similar methodologies, including the use of disk diffusion and well diffusion methods to assess the inhibitory effects of P. aeruginosa strains against target pathogens. Enzyme production was analyzed through various biochemical assays to determine the diversity and frequencies of enzyme secretion among the strains; (3) Results: A comparative analysis of enzyme production in P. aeruginosa strains from clinical sources revealed significant variations in enzyme production, with hemolysin and protease being the most commonly produced enzymes. Gelatinase production showed lower rates, whereas chondroitinase and hyaluronidase were absent or occurred less frequently. In contrast, a comparative analysis of enzyme production in environmental isolates showed different patterns, indicating adaptation to environmental conditions. Pyocyanin production was absent in all environmental isolates. The inhibitory effects against gram-positive and gram-negative bacteria varied among different P. aeruginosa strains, with strain-specific variations observed. Limited inhibitory effects were observed against fungi, primarily toward gram-positive bacteria; (4) Conclusions: The findings highlight the strain-specific nature of inhibitory effects and enzyme production in P. aeruginosa strains. The correlation between enzyme production and inhibitory effects against gram-positive bacteria suggest a potential role of specific enzymes, such as hemolysin and protease, in the antimicrobial activity. The complexity of the relationship between enzyme production and the inhibition of different pathogens requires further investigation. The results emphasize the potential of P. aeruginosa strains as sources for antimicrobial strategies, particularly against gram-positive bacteria. Future research should focus on understanding the mechanisms underlying these inhibitory effects and exploring their therapeutic applications.