University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 06 01 Editorial of vol. 14 no. 54 Editorial of vol. 14 no. 54 30428 FA Journal Article 2026 05 26 https://bjm.ui.ac.ir/article_30428_11084fa2d19d8de966bfef2c220f11a8.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 08 23 Enhancing β-Carotene production in the mold Blakeslea Trispora under imidazole stress via Adaptive Laboratory Evolution Enhancing β-Carotene production in the mold Blakeslea Trispora under imidazole stress via Adaptive Laboratory Evolution 1 14 29820 10.22108/bjm.2025.146152.1644 FA Hamideh Moradi Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran Davood Zare Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran Mehrdad Azin Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran Hamid Moghimi Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran Journal Article 2025 07 29 Beta-carotene, a natural plant pigment belonging to the carotenoid family, is one of the most important carotenoids. It is widely used as a precursor of vitamin A in pharmaceuticals, food, feed, and other applications. Due to its high capacity for carotenoid production, the heterothallic fungus Blakeslea trispora is considered one of the main biological sources of these compounds. Trisporic acids act as sexual hormones between the two mating types and are key regulators of carotenoid biosynthesis. This study used an adaptive laboratory evolution (ALE) approach involving selective pressure with imidazole to develop new strains of this mold. The results showed that one of the adapted strains exhibited a significant increase in the expression of genes involved in carotenoid biosynthesis. These genes included carRA, which encodes lycopene cyclase and phytoene synthase; carG, which is involved in geranylgeranyl pyrophosphate synthase, and Sr5AL, which is a key gene related to the trisporic acid response. Regardless of the presence of exogenously added trisporic acids, a 2.5-fold increase in Sr5AL transcription positively influenced β-carotene production in one of the imidazole-adapted strains. These results suggest that β-carotene producing strains could be optimized using evolutionary approaches combined with controlled stress conditions. Beta-carotene, a natural plant pigment belonging to the carotenoid family, is one of the most important carotenoids. It is widely used as a precursor of vitamin A in pharmaceuticals, food, feed, and other applications. Due to its high capacity for carotenoid production, the heterothallic fungus Blakeslea trispora is considered one of the main biological sources of these compounds. Trisporic acids act as sexual hormones between the two mating types and are key regulators of carotenoid biosynthesis. This study used an adaptive laboratory evolution (ALE) approach involving selective pressure with imidazole to develop new strains of this mold. The results showed that one of the adapted strains exhibited a significant increase in the expression of genes involved in carotenoid biosynthesis. These genes included carRA, which encodes lycopene cyclase and phytoene synthase; carG, which is involved in geranylgeranyl pyrophosphate synthase, and Sr5AL, which is a key gene related to the trisporic acid response. Regardless of the presence of exogenously added trisporic acids, a 2.5-fold increase in Sr5AL transcription positively influenced β-carotene production in one of the imidazole-adapted strains. These results suggest that β-carotene producing strains could be optimized using evolutionary approaches combined with controlled stress conditions.

https://bjm.ui.ac.ir/article_29820_982672f06aa3da0396917a5b4f142708.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 08 23 Investigation of prevalence of biocide resistance genes qac A/B, smr and nor A in Staphylococcus aureus isolates and susceptibility of these isolates to Benzalkonium chloride Investigation of prevalence of biocide resistance genes qac A/B, smr and nor A in Staphylococcus aureus isolates and susceptibility of these isolates to Benzalkonium chloride 15 47 29816 10.22108/bjm.2025.145388.1635 FA Zahra Samsami Department of biology, Kavian Institute of Higher Education, Mashhad, Iran Nazanin Ataee Department of biology, Kavian Institute of Higher Education, Mashhad, Iran Atefeh Sarafan Sadeghi Food quality control & hygiene department in Varastegan institute for medical science, Mashhad, Iran Davood Mansury Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mahboubeh Derakhshani Department of biology, Kavian Institute of Higher Education, Mashhad, Iran Journal Article 2025 05 29 Staphylococcus aureus is a major cause of hospital-acquired infections. Quaternary ammonium compounds (QACs) are widely used as antiseptics in healthcare facilities to prevent such infections. This study investigated the prevalence of genes conferring resistance to benzalkonium chloride, a common QAC, in S. aureus strains. A total of 150 Staphylococcus isolates were collected from various wards of Mashhad hospitals. Diagnostic tests confirmed that 100 of these isolates were S. aureus, including 52 that were identified as methicillin-resistant S. aureus (MRSA). Antimicrobial susceptibility was determined using the disk diffusion method with 10 common antibiotics, and MRSA strains were confirmed using cefoxitin disks. The minimum inhibitory concentration (MIC) of benzalkonium chloride was measured to assess the sensitivity of the isolates. Finally, the presence of antiseptic resistance genes, specifically qacA/B, smr, and norA, was investigated in all isolates using the polymerase chain reaction (PCR) method. The highest level of resistance was to penicillin (85%), followed by erythromycin (50%), amikacin (45%), ciprofloxacin (38%), doxycycline (36%), clindamycin (33%), tobramycin (27%), trimethoprim-sulfamethoxazole (23%), gentamicin (19%), and cefoxitin (52%) among the S. aureus isolates. The MIC range for benzalkonium chloride was 0.01 – 2 µg/mL. Molecular analysis revealed that the qacA/B, smr and norA genes were present in 37%, 49% and 41% of the isolates, respectively. These results suggest that benzalkonium chloride remains an effective disinfectant. However, penicillin resistance in S. aureus has increased significantly over time, rendering benzalkonium chloride less effective. The study also found that the smr gene was more prevalent than the qacA/B and norA genes in these isolates. Staphylococcus aureus is a major cause of hospital-acquired infections. Quaternary ammonium compounds (QACs) are widely used as antiseptics in healthcare facilities to prevent such infections. This study investigated the prevalence of genes conferring resistance to benzalkonium chloride, a common QAC, in S. aureus strains. A total of 150 Staphylococcus isolates were collected from various wards of Mashhad hospitals. Diagnostic tests confirmed that 100 of these isolates were S. aureus, including 52 that were identified as methicillin-resistant S. aureus (MRSA). Antimicrobial susceptibility was determined using the disk diffusion method with 10 common antibiotics, and MRSA strains were confirmed using cefoxitin disks. The minimum inhibitory concentration (MIC) of benzalkonium chloride was measured to assess the sensitivity of the isolates. Finally, the presence of antiseptic resistance genes, specifically qacA/B, smr, and norA, was investigated in all isolates using the polymerase chain reaction (PCR) method. The highest level of resistance was to penicillin (85%), followed by erythromycin (50%), amikacin (45%), ciprofloxacin (38%), doxycycline (36%), clindamycin (33%), tobramycin (27%), trimethoprim-sulfamethoxazole (23%), gentamicin (19%), and cefoxitin (52%) among the S. aureus isolates. The MIC range for benzalkonium chloride was 0.01 – 2 µg/mL. Molecular analysis revealed that the qacA/B, smr and norA genes were present in 37%, 49% and 41% of the isolates, respectively. These results suggest that benzalkonium chloride remains an effective disinfectant. However, penicillin resistance in S. aureus has increased significantly over time, rendering benzalkonium chloride less effective. The study also found that the smr gene was more prevalent than the qacA/B and norA genes in these isolates.

https://bjm.ui.ac.ir/article_29816_321d5b4a073d82fb721422785230cb09.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 08 23 Investigation of the Symbiotic Relationship Between Oak and the Fungus Tuber aestivum in Enhancing Vegetative Growth Investigation of the Symbiotic Relationship Between Oak and the Fungus Tuber aestivum in Enhancing Vegetative Growth 49 65 29865 10.22108/bjm.2025.145257.1634 FA Parvin Bagherifar Silviculture and Forest Ecology, Department of Silviculture and Forest Ecology, Faculty of Forest Sciences, Gorgan University of Agriculture Sciences and Natural Resources, Gorgan, I.R. Iran. Seyed Mohammad Waez-Mousavi Department of Silviculture and Forest Ecology, Faculty of Forest Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, I.R. Iran. Kamran Rahnama Department of Plant Protection, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, I.R. Iran. Journal Article 2025 05 13 Quercus macranthera, as one of the important forest species in Iran, requires special attention in forest restoration and development programs due to its ecological and economic characteristics. The present study examined the effect of the ectomycorrhizal symbiosis between the summer black truffle fungus, T. aestivum, and Quercus macranthera seedlings over a period of 16 months (March 2020 to September 2021) at the Shast Kalateh Forest Educational and Research Nursery in Gorgan. One-year-old seedlings were divided into two groups: a control group and a treatment group inoculated with fungal spores. The spore suspension was applied to the potting substrate, followed by manual watering. Formation of mycorrhizal symbiosis was assessed microscopically using both visual inspection and the gridline intersect method. Evaluation of growth parameters, including stem height, collar diameter, and number of leaves, after two inoculation stages, revealed a highly significant difference (p < 0.01) between the treatment groups. Seedlings inoculated with the fungus exhibited marked improvements in growth indices alongside the development of extensive mycorrhizal networks on their roots. Microscopic observations showed that the roots of inoculated seedlings were more robust and better organized, enhancing water and nutrient uptake efficiency. The findings of this study demonstrated that inoculation of Q. macranthera seedlings with the ectomycorrhizal fungus T. aestivum significantly enhanced vegetative growth parameters and markedly increased the development of extensive mycorrhizal networks in the roots. This growth enhancement plays a crucial role in improving plant resilience against environmental stresses, particularly drought and salinity. From an ecological standpoint, ectomycorrhizal symbiosis has the potential to augment biodiversity and accelerate the sustainable restoration of oak forest ecosystems. Furthermore, sustainable cultivation of T. aestivum can contribute to local economic development and generate sustainable employment opportunities in rural communities. The results indicate that inoculation of Q. macranthera seedlings with T. aestivum constitutes an effective, sustainable, and environmentally friendly strategy for promoting growth, enhancing productivity, and increasing seedling survival in reforestation projects. For the widespread application of this technology, it is essential to conduct interdisciplinary and long-term field studies to assess seedling persistence and survival in natural habitats, as well as to evaluate the environmental and ecological effects of this symbiosis on diverse plant species. Furthermore, sustainable cultivation of T. aestivum can contribute to local economic development and generate sustainable employment opportunities in rural communities. The results indicate that inoculation of Q. macranthera seedlings with T. aestivum constitutes an effective, sustainable, and environmentally friendly strategy for promoting growth, enhancing productivity, and increasing seedling survival in reforestation projects. For the widespread application of this technology, it is essential to conduct interdisciplinary and long-term field studies to assess seedling persistence and survival in natural habitats, as well as to evaluate the environmental and ecological effects of this symbiosis on diverse plant species. Quercus macranthera, as one of the important forest species in Iran, requires special attention in forest restoration and development programs due to its ecological and economic characteristics. The present study examined the effect of the ectomycorrhizal symbiosis between the summer black truffle fungus, T. aestivum, and Quercus macranthera seedlings over a period of 16 months (March 2020 to September 2021) at the Shast Kalateh Forest Educational and Research Nursery in Gorgan. One-year-old seedlings were divided into two groups: a control group and a treatment group inoculated with fungal spores. The spore suspension was applied to the potting substrate, followed by manual watering. Formation of mycorrhizal symbiosis was assessed microscopically using both visual inspection and the gridline intersect method. Evaluation of growth parameters, including stem height, collar diameter, and number of leaves, after two inoculation stages, revealed a highly significant difference (p < 0.01) between the treatment groups. Seedlings inoculated with the fungus exhibited marked improvements in growth indices alongside the development of extensive mycorrhizal networks on their roots. Microscopic observations showed that the roots of inoculated seedlings were more robust and better organized, enhancing water and nutrient uptake efficiency. The findings of this study demonstrated that inoculation of Q. macranthera seedlings with the ectomycorrhizal fungus T. aestivum significantly enhanced vegetative growth parameters and markedly increased the development of extensive mycorrhizal networks in the roots. This growth enhancement plays a crucial role in improving plant resilience against environmental stresses, particularly drought and salinity. From an ecological standpoint, ectomycorrhizal symbiosis has the potential to augment biodiversity and accelerate the sustainable restoration of oak forest ecosystems. Furthermore, sustainable cultivation of T. aestivum can contribute to local economic development and generate sustainable employment opportunities in rural communities. The results indicate that inoculation of Q. macranthera seedlings with T. aestivum constitutes an effective, sustainable, and environmentally friendly strategy for promoting growth, enhancing productivity, and increasing seedling survival in reforestation projects. For the widespread application of this technology, it is essential to conduct interdisciplinary and long-term field studies to assess seedling persistence and survival in natural habitats, as well as to evaluate the environmental and ecological effects of this symbiosis on diverse plant species. Furthermore, sustainable cultivation of T. aestivum can contribute to local economic development and generate sustainable employment opportunities in rural communities. The results indicate that inoculation of Q. macranthera seedlings with T. aestivum constitutes an effective, sustainable, and environmentally friendly strategy for promoting growth, enhancing productivity, and increasing seedling survival in reforestation projects. For the widespread application of this technology, it is essential to conduct interdisciplinary and long-term field studies to assess seedling persistence and survival in natural habitats, as well as to evaluate the environmental and ecological effects of this symbiosis on diverse plant species.

https://bjm.ui.ac.ir/article_29865_5883ee79e6dab14b4ea1742853373415.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 08 23 Isolation and Identification of Fusarium Species Associated with Wild grass in Wheat Fields of Western Iran and Major Mycotoxins Produced Isolation and Identification of Fusarium Species Associated with Wild grass in Wheat Fields of Western Iran and Major Mycotoxins Produced 67 82 29913 10.22108/bjm.2025.146247.1647 FA Maryam Karami Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran Dustmorad Zafari Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran Khosrow Chehri Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran Journal Article 2025 08 05 Fusarium species are widespread phytopathogenic fungi that pose threats to agriculture, ecosystems, and food safety due to their ability to produce harmful mycotoxins. This study aimed to assess the species diversity and toxigenic potential of Fusarium isolates obtained from wild grasses in wheat and barley fields in western Iran. A total of 264 Fusarium isolates were identified morphologically, and 20 representative isolates were selected for multilocus phylogenetic analysis using the TEF-1α and CAL1 gene regions. Phylogenetic reconstruction identified nine distinct Fusarium species, including F. solani, F. proliferatum, F. oxysporum, F. avenaceum, F. acuminatum, F. culmorum, F. brachygibbosum, F. incarnatum, and F. equiseti. PCR assays using gene-specific primers detected FUM1 and PKS4 genes in 50% of F. proliferatum and 32% of F. equiseti isolates, respectively, indicating their potential to produce fumonisins and zearalenone. The highest frequency of toxigenic isolates was observed in Kermanshah, Hamedan, and Lorestan provinces. These results underscore the phylogenetic diversity and toxigenic capacity of Fusarium populations in natural habitats and highlight the importance of monitoring native fungal communities to reduce potential agricultural and health risks. Fusarium species are widespread phytopathogenic fungi that pose threats to agriculture, ecosystems, and food safety due to their ability to produce harmful mycotoxins. This study aimed to assess the species diversity and toxigenic potential of Fusarium isolates obtained from wild grasses in wheat and barley fields in western Iran. A total of 264 Fusarium isolates were identified morphologically, and 20 representative isolates were selected for multilocus phylogenetic analysis using the TEF-1α and CAL1 gene regions. Phylogenetic reconstruction identified nine distinct Fusarium species, including F. solani, F. proliferatum, F. oxysporum, F. avenaceum, F. acuminatum, F. culmorum, F. brachygibbosum, F. incarnatum, and F. equiseti. PCR assays using gene-specific primers detected FUM1 and PKS4 genes in 50% of F. proliferatum and 32% of F. equiseti isolates, respectively, indicating their potential to produce fumonisins and zearalenone. The highest frequency of toxigenic isolates was observed in Kermanshah, Hamedan, and Lorestan provinces. These results underscore the phylogenetic diversity and toxigenic capacity of Fusarium populations in natural habitats and highlight the importance of monitoring native fungal communities to reduce potential agricultural and health risks.

https://bjm.ui.ac.ir/article_29913_2a28d1e59ed624ae777c0a8bc8963e47.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 08 23 Isolation, Screening, and Optimization of Laccase Production from Yeast: A Novel Approach in the Synthesis of Bioactive Hydrogels Isolation, Screening, and Optimization of Laccase Production from Yeast: A Novel Approach in the Synthesis of Bioactive Hydrogels 83 104 29973 10.22108/bjm.2025.146566.1650 FA Soheila Abbasi Department of Cellular and Molecular Microbiology, Faculty of Biological Sciences and Technologies, University of Isfahan, Isfahan. Fariba Esmaeili Department of Plant and Animal Biology, Faculty of Biological Sciences and Technologies, University of Isfahan, Isfahan, Iran. Fatemeh Zahara Ghazavi Department of Cellular and Molecular Microbiology, Faculty of Biological Sciences and Technologies, University of Isfahan, Isfahan, Journal Article 2025 09 05 Laccases are a diverse group of multicopper oxidases that catalyze the oxidation of a wide range of aromatic compounds. These enzymes act on various phenolic and non-phenolic, as well as inorganic substrates. Owing to their strong oxidative potential, laccases are capable of degrading highly recalcitrant compounds, thereby playing a crucial role in pollutant removal. They are widely distributed in nature, occurring in numerous plants, fungi, bacteria, and even some insects. Environmental samples were cultured on yeast extract–glucose agar, and the isolated yeast strains were subjected to qualitative screening using guaiacol, ABTS, acetaminophen, and catechol as indicator substrates. A high potential laccase-producing strain was selected through quantitative assays. Culture conditions were optimized with respect to temperature, carbon source, and nitrogen source. The enzyme was subsequently purified and applied to the preparation of chitosan/gelatin hydrogels containing Kochia scoparia extract. Following qualitative and quantitative screening, the strain Rhodotorula mucilaginosa ASAA1404 was identified as the superior producer, with a laccase activity of 50.6 IU/L. Glucose and yeast extract were found to be the most effective carbon and nitrogen sources, respectively, and the optimal cultivation temperature was 25 °C. The resulting hydrogels exhibited notable antibacterial activity against Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. This study demonstrates that laccase production by yeast and its incorporation within biocompatible hydrogel matrices represent a novel and sustainable strategy for developing advanced systems in biotechnology, medicine, and environmental applications. Laccases are a diverse group of multicopper oxidases that catalyze the oxidation of a wide range of aromatic compounds. These enzymes act on various phenolic and non-phenolic, as well as inorganic substrates. Owing to their strong oxidative potential, laccases are capable of degrading highly recalcitrant compounds, thereby playing a crucial role in pollutant removal. They are widely distributed in nature, occurring in numerous plants, fungi, bacteria, and even some insects. Environmental samples were cultured on yeast extract–glucose agar, and the isolated yeast strains were subjected to qualitative screening using guaiacol, ABTS, acetaminophen, and catechol as indicator substrates. A high potential laccase-producing strain was selected through quantitative assays. Culture conditions were optimized with respect to temperature, carbon source, and nitrogen source. The enzyme was subsequently purified and applied to the preparation of chitosan/gelatin hydrogels containing Kochia scoparia extract. Following qualitative and quantitative screening, the strain Rhodotorula mucilaginosa ASAA1404 was identified as the superior producer, with a laccase activity of 50.6 IU/L. Glucose and yeast extract were found to be the most effective carbon and nitrogen sources, respectively, and the optimal cultivation temperature was 25 °C. The resulting hydrogels exhibited notable antibacterial activity against Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. This study demonstrates that laccase production by yeast and its incorporation within biocompatible hydrogel matrices represent a novel and sustainable strategy for developing advanced systems in biotechnology, medicine, and environmental applications.

https://bjm.ui.ac.ir/article_29973_7517232d76053e920f7b755351888b5a.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 14 54 2025 06 22 Zinc-enriched probiotic yeasts: A novel strategy in biofortification to improve human nutrition and animal feed Zinc-enriched probiotic yeasts: A novel strategy in biofortification to improve human nutrition and animal feed 105 128 29946 10.22108/bjm.2025.146706.1652 FA Maedeh Hajkazemian Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran Masumeh Sadat Shahidi Rizi Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran Maryam Jalili Tabaii Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran Journal Article 2025 09 18 Probiotics, as microorganisms that affect host health in a positive way, have increasingly garnered attention. Although most research has focused on probiotic bacteria, yeast probiotics — owing to their unique characteristics and advantages — have successfully established their position in this field. Among essential elements required by the body, zinc (Zn) plays a crucial role in both humans and animals. Its deficiency is recognized as a key form of malnutrition globally, profoundly affecting human health, cognitive development and overall growth, as well as productivity in animal husbandry. Common mineral supplements such as zinc sulfate are often limited by low bioavailability and gastrointestinal side effects. Yeast-based probiotic biofortification is a novel strategy designed to overcome these limitations and effectively alleviate zinc deficiency. Cultivating yeast in zinc-enriched media results in efficient intracellular accumulation of zinc in a more bioavailable organic form. This dual-purpose product not only serves as a superior zinc source but also retains the probiotic properties of the yeast, leading to synergistic effects that enhance intestinal barrier function, modulate the immune system, and improve gut microbiota balance. Zinc-enriched yeasts could offer a promising and sustainable solution to zinc deficiency. However, challenges remain regarding industrial scalability, stability, and regulatory compliance, necessitating further research. This article aims to provide a concise review of studies focusing on zinc-accumulating probiotic yeasts, mechanisms of zinc uptake and storage in yeast, and the processes governing zinc absorption from fortified yeast in humans. Probiotics, as microorganisms that affect host health in a positive way, have increasingly garnered attention. Although most research has focused on probiotic bacteria, yeast probiotics — owing to their unique characteristics and advantages — have successfully established their position in this field. Among essential elements required by the body, zinc (Zn) plays a crucial role in both humans and animals. Its deficiency is recognized as a key form of malnutrition globally, profoundly affecting human health, cognitive development and overall growth, as well as productivity in animal husbandry. Common mineral supplements such as zinc sulfate are often limited by low bioavailability and gastrointestinal side effects. Yeast-based probiotic biofortification is a novel strategy designed to overcome these limitations and effectively alleviate zinc deficiency. Cultivating yeast in zinc-enriched media results in efficient intracellular accumulation of zinc in a more bioavailable organic form. This dual-purpose product not only serves as a superior zinc source but also retains the probiotic properties of the yeast, leading to synergistic effects that enhance intestinal barrier function, modulate the immune system, and improve gut microbiota balance. Zinc-enriched yeasts could offer a promising and sustainable solution to zinc deficiency. However, challenges remain regarding industrial scalability, stability, and regulatory compliance, necessitating further research. This article aims to provide a concise review of studies focusing on zinc-accumulating probiotic yeasts, mechanisms of zinc uptake and storage in yeast, and the processes governing zinc absorption from fortified yeast in humans.

https://bjm.ui.ac.ir/article_29946_2d6a07d5879d05349815f4aee222562c.pdf