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The valorization of industrial waste in the production of new products is a growing trend, with food waste showing significant promise as a raw material for various industries. Thus, this research aimed to investigate the production of Geotrichum candidum lipase using industrial waste, such as mozzarella cheese whey (MCW) and corn steep liquor (CSL), and to analyze how effectively it catalyzes the esterification of oleic acid with methanol. Lipase production was carried out in medium containing MCW and CSL, with fermentation conditions optimized using a fractional factorial experimental design and central composite experimental design. The highest activities (16.71 U/mL in 24 h and 17.80 U/mL in 48 h) were found in conditions of 13.6% (%w/v) CSL and 37.1% (%w/v) MCW, with corn oil fixed at 1% (%w/v) and pH fixed at 6,00. Esterification conditions were evaluated at atmospheric pressure, both in a solvent-free environment and using hexane, as well as under high pressures with supercritical carbon dioxide (SC-CO2). The produced lipase demonstrated high catalytic activity for the esterification reaction of oleic acid with methanol under SC-CO2 with an increase of 39.41% in the yield. The yields found confirm the feasibility of producing lipase from industrial waste, thus presenting it as a sustainable and efficient alternative for industrial processes, and show that there is no need to use toxic organic solvents in esterification reactions. [ABSTRACT FROM AUTHOR]

Abstract Xiaozhou mustard (Brassica napiformis) root tuber, a traditional fermented vegetable, has a long history in Rongan County, Guangxi Province. However, the frequent occurrence of root tuber sour rot by Geotrichum candidum (G. candidum) has seriously reduced Xiaozhou mustard production and quality in recent years. The objective of the present study is to investigate the antifungal efficacy of 2-chloro-5-trifluoromethoxybenzeneboronic acid (Cl-F-BBA) against G. candidum and its possible mechanisms. The results revealed that a concentration of 0.25 mg/mL Cl-F-BBA completely halted mycelial growth and spore germination. Furthermore, a slightly lower concentration of 0.20 mg/mL was sufficient to compromise the integrity of the plasma membrane in mycelia and mitochondria, leading to a reduction in respiratory rate, activities of malate dehydrogenase (MDH), and succinate dehydrogenase (SDH), ATP content, and energy charge. This concentration also significantly disordered antioxidant metabolism, resulting in the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and caused intracellular leakage in mycelia. In vivo experiments further demonstrated that Xiaozhou mustard root tubers treated with Cl-F-BBA exhibited markedly lower decay rates and lesion diameters compared to the control group. In summary, Cl-F-BBA presents a promising solution for controlling root tuber sour rot in Xiaozhou mustard caused by G. candidum.

Mustard essential oil (MEO) nanoemulsions fortified with citrus pectin and tween-80 (MEO-NE-PT) or tween-80 (MEO-NE-T) were prepared by high-pressure homogenization followed by ultrasonication, and comparative analysis was performed on the microstructure, storage stability, pH, ionic strength and thermal tolerance between MEO-NE-PT and MEO-NE-T. The application of MEO-NE-PT to the postharvest preservation of ‘Shatangju’ mandarin was evaluated. It was found that MEO-NE-PT exhibited superior stability with smaller fluctuations in particle size and polydispersity index (PDI). The minimum inhibitory concentration (MIC) of MEO-NE-PT was 64 μL/L, much lower than those of MEO (256 μL/L) and MEO-NE-T (128 μL/L). Furthermore, after MEO-NE-PT treatment at 64 μL/L for 6 h, the germination rate of Geotrichum candidum spores was only 6.67%, and the length of the germ tube was only 8.57 μm, both significantly lower than 100% and 165.02 μm for the control group (MEO), respectively. The results of scanning electron microscopy (SEM) revealed that treatment with MEO-NE-PT caused the mycelium of Geotrichum candidum to wrinkle and break apart. Compared with the control group, MEO-NE-PT treatment could significantly reduce the decay rate and quality loss of ‘Shatangju’ mandarin, while delaying the decline in hardness and total soluble solids. As a safe and effective antimicrobial agent, MEO-NE-PT could control the growth of Geotrichum candidum and maintain the post-harvest quality of ‘Shatangju’ mandarin.

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In this study, the chemical compositions of rosemary (Rosmarinus officinalis Spenn.) and sweet marjoram (Origanum majorana L.) essential oils, both individually and in various blend ratios, were investigated by using Gas Chromatography-Mass Spectrometry. Their antifungal activities were also determined against the potato rubbery rot disease agent, Geotrichum candidum, under in vitro and in vivo conditions. Camphor (20.69%) and terpinen-4-ol (35.13%) were determined as primary constituents in rosemary and sweet marjoram essential oils, respectively. Sweet marjoram and rosemary essential oils completely inhibited mycelial growth of G. candidum at 55.0 and 65.0 µL/Petri concentrations, respectively. Essential oils at these concentrations were found as fungicidal. Notably, a synergistic fungicidal antifungal effects were also observed in essential oil blends. Blend of sweet marjoram and rosemary essential oil in a 3:1 ratio (O75R25) significantly enhanced antifungal activity at the relatively lower concentration (45.0 µL/Petri). Microscopic observations revealed structural deformations in exposed hyphae, including cytoplasmic coagulation and vacuolization. Essential oil blend (O75R25), sweet marjoram and rosemary essential oils completely inhibited the disease lesion caused by G. candidum on potato tubers at concentrations of 100.0, 125.0, and 150.0 µL/L air, respectively. These findings emphasized that essential oil blends of rosemary and sweet marjoram have synergistic antifungal potential and can be used as effective biofungicides against plant fungal diseases. [ABSTRACT FROM AUTHOR]

Fungi inflict a great deal of damage to crops in fields and in storage facilities, causing issues such as leaf spot, wilt, rust, dieback and rot, as well as releasing mycotoxins that taint vegetation. In the current study, 25 de novo fungal isolates were taken from infected plant tissue (leaf, root and fruit), at pre- and post-harvest stages. Isolates were identified using molecular markers; 8 genera and 15 species were determined. The most common species was Penicillium spp. (40%), Aspergillus spp. (20%), Fusarium spp. (16%) and Alternaria alternata species (8%). The remaining 16% was comprised of various types of fungi, including Geotrichum candidum, Neofusicoccum parvum, Rhizopus stolonifera and Mucor fragilis. Many of these genera are known to cause significant crop damage and are notorious mycotoxin producers. An evaluation of the optimal growth temperature revealed the ideal temperatures were 30 °C for 56% of isolates, 25 °C for 28% of isolates and 20 °C for 16% of isolates. An assessment of water activity showed that 60% of isolates belonged to Penicillium and Aspergillus spp. and were mesophilic and xerophilic. Another 28% of isolates were Fusarium spp., Geotrichum candidum, Neofusicoccum parvum and Mucor fragilis, and hydrophilic. The remaining 12%, representing Alternaria alternata and Rhizopus stolonifera, were mesophilic. The current study provides accurate eco-physiological response data and molecular information for each isolate. The findings can assist the development of novel approaches to control the expansion of invasive fungal infections and minimise their deleterious consequences. [ABSTRACT FROM AUTHOR]

When firm implantation has occurred, pregnancy losses during the late embryonic or early fetal period are less common and typically occur before 60 days of gestation. A rare case of early fetal death due to Geotrichum candidum infection in a pluriparous Jersey crossbred cow was sporadically recorded during routine screening at the university cattle farm. The early fetal death was diagnosed using sequential sonographic examinations, and the aetiology was confirmed through microbiological examination and histopathological evaluation of an endometrial biopsy sample. It is concluded that, although mycotic abortions and fetal deaths are uncommon and sporadic, routine screening of cows for late embryonic and early fetal death remains essential. [ABSTRACT FROM AUTHOR]

Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador's animal feed industry. The emergence of yellow-orange fungal growth in PKC on some cattle farms in Ecuador sparked concerns within the cattle industry regarding a potential mycotoxin-producing fungus on this substrate. Due to the limited availability of analytical chemistry techniques in Ecuador for mycotoxin detection, we chose to isolate and identify the fungus to determine its association with mycotoxin-producing genera. Through molecular identification via ITS region sequencing, we identified the yellow-orange fungus as the yeast Candida ethanolica. Furthermore, we isolated two other fungi—the yeast Pichia kudriavzevii, and the fungus Geotrichum candidum. Molecular identification confirmed that all three species are not classified as mycotoxin-producing fungi but in contrast, the literature indicates that all three have demonstrated antifungal activity against Aspergillus and Penicillium species, genera associated with mycotoxin production. This suggests their potential use in biocontrol to counter the colonization of harmful fungi. We discuss preventive measures against the fungal invasion of PKC and emphasize the importance of promptly identifying fungi on this substrate. Rapid recognition of mycotoxin-producing and pathogenic genera holds the promise of mitigating cattle intoxication and the dissemination of mycotoxins throughout the food chain. [ABSTRACT FROM AUTHOR]

Geotrichum candidum is a dimorphic yeast used in cheese processing. To our knowledge, no major metabolites have been identified to date in G. candidum except for some amino acid and fatty acid metabolites. This has limited research on the commercial use of G. candidum. In this study, we aimed to analyze temporal changes in the intra- and extra-cellular metabolites of G. candidum and Saccharomyces cerevisiae cultured in YM medium as reference. As a result of metabolite analysis, it was observed that G. candidum tends to accumulate pentose phosphate pathway compounds, which are involved in nucleic acid synthesis, after 48 h of cultivation when compared to S. cerevisiae. In addition, G. candidum accumulated higher amounts of the antioxidant glutathione in the medium than did S. cerevisiae. In addition, G. candidum accumulated large amounts of B vitamins such as pantothenic acid and nicotinic acid in the medium. Finally, we examined the potential of G. candidum as a host for the production of useful compounds such as pantothenic acid. When cultured in medium supplemented with the pantothenic acid precursor β-alanine, G. candidum produced 12-fold higher amounts of pantothenic acid (30 μM) than that by S. cerevisiae. This study indicates that G. candidum accumulates various useful compounds that are dissimilar to those produced by S. cerevisiae. Furthermore, G. candidum has the potential to produce useful chemicals under appropriate culture conditions. [ABSTRACT FROM AUTHOR]

Pectinases are applied in many commercial processes, particularly for fruit juice clarification. Cost effective production of pectinase necessitates utilization of agro-industrial wastes as fermentation raw materials. Biomass from halophytic plants provides a prospect for its sustainable utilization in industrial processes. Here, we report utilization of two halophytic biomasses, Suaeda fruticosa and Cressa cretica to grow a pectinolytic strain, Geotrichum candidum AA15 and its mutant strain AHC1. Amount of pectinase produced was compared by cultivating the strains in the medium containing apple peels and orange peels. The data showed that G. candidum AHC1 can produce pectinase titers of 15.43 and 28.15 IU mL−1 within 25 h when cultivated in the medium containing biomass from C. cretica and S. fruticosa, respectively. The results of FTIR and Scanning Electron microscopy affirmed the bacterial growth mediated changes in the structure of the substrate that was associated with the pectinase production. The crude pectinase preparation was applied to hydrolyze an agro-waste, sugarcane bagasse, that resulted in the release of 86 mg g−1 of reducing sugars. Thus, this study proposed the usage of halophytic plant biomass for cost effective pectinase production and its application for saccharification of agro-waste. [ABSTRACT FROM AUTHOR]

Enzymes are biocatalysts mainly used for their industrial potential in various applications. The present study aims to understand the enzyme production for biotechnological interest from a local yeast strain. From 100 isolates obtained from various biotopes, 78 strains were selected for their enzymatic heritage. Screening of a-amylase, lipase/esterase, and cellulase activities by rapid plate detection methods was carried out and the PO27 yeast was selected for its high capacity to produce a-amylase. In addition, this yeast strain exhibited good lipolytic and esterolytic activities, as well as low cellulase activity. A sequence analysis of the D1/D2 region of the 26S ribosomal RNA (26S rRNA) and a study of morphological characteristics identified the PO27 strain as Geotrichum candidum. The production of a-amylase has been studied in solid medium fermentation using various natural substrates without any supplementation such as olive pomace, potato peels, leftover bread, and mastic cake. G. candidum PO27 showed an improved production of a-amylase with olive pomace, thus reaching approximately 180.71 U/g. To evaluate the ability of this isolate to produce a-amylase in submerged fermentation, multiple concentrations of olive pomace substrate were tested. The best activity of submerged fermentation was statistically compared to the solid-state fermentation result in order to select the appropriate fermentation type. A high significant difference was found to rank the 6% olive pomace medium as the best substrate concentration with 34.395 U/mL of a-amylase activity. This work showed that the new isolate Geotrichum candidum PO27 has a better potential to produce a-amylase at a low cost in solid-state fermentation compared to submerged fermentation. Optimization conditions for PO27 a-amylase production through solid-state fermentation were achieved using a one factor at a time (OFAT) approach. The findings revealed that a high temperature (60 °), an acidic pH, malt extract, and soluble starch were the highly significant medium components for enhancing a-amylase production. The use of olive pomace waste by Geotrichum candidum PO27 is expected to be effective in producing an industrially useful a-amylase. [ABSTRACT FROM AUTHOR]

Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador’s animal feed industry. The emergence of yellow-orange fungal growth in PKC on some cattle farms in Ecuador sparked concerns within the cattle industry regarding a potential mycotoxin-producing fungus on this substrate. Due to the limited availability of analytical chemistry techniques in Ecuador for mycotoxin detection, we chose to isolate and identify the fungus to determine its association with mycotoxin-producing genera. Through molecular identification via ITS region sequencing, we identified the yellow-orange fungus as the yeast Candida ethanolica. Furthermore, we isolated two other fungi—the yeast Pichia kudriavzevii, and the fungus Geotrichum candidum. Molecular identification confirmed that all three species are not classified as mycotoxin-producing fungi but in contrast, the literature indicates that all three have demonstrated antifungal activity against Aspergillus and Penicillium species, genera associated with mycotoxin production. This suggests their potential use in biocontrol to counter the colonization of harmful fungi. We discuss preventive measures against the fungal invasion of PKC and emphasize the importance of promptly identifying fungi on this substrate. Rapid recognition of mycotoxin-producing and pathogenic genera holds the promise of mitigating cattle intoxication and the dissemination of mycotoxins throughout the food chain.

Xiaozhou mustard (Brassica napiformis) root tuber, a traditional fermented vegetable, has a long history in Rongan County, Guangxi Province. However, the frequent occurrence of root tuber sour rot by Geotrichum candidum (G. candidum) has seriously reduced Xiaozhou mustard production and quality in recent years. The objective of the present study is to investigate the antifungal efficacy of 2-chloro-5-trifluoromethoxybenzeneboronic acid (Cl-F-BBA) against G. candidum and its possible mechanisms. The results revealed that a concentration of 0.25 mg/mL Cl-F-BBA completely halted mycelial growth and spore germination. Furthermore, a slightly lower concentration of 0.20 mg/mL was sufficient to compromise the integrity of the plasma membrane in mycelia and mitochondria, leading to a reduction in respiratory rate, activities of malate dehydrogenase (MDH), and succinate dehydrogenase (SDH), ATP content, and energy charge. This concentration also significantly disordered antioxidant metabolism, resulting in the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and caused intracellular leakage in mycelia. In vivo experiments further demonstrated that Xiaozhou mustard root tubers treated with Cl-F-BBA exhibited markedly lower decay rates and lesion diameters compared to the control group. In summary, Cl-F-BBA presents a promising solution for controlling root tuber sour rot in Xiaozhou mustard caused by G. candidum., (© 2024. The Author(s).)

To investigate the usefulness of encapsulation technique in aquaculture feed, 11 weeks feeding experiment was designed to check in vivo comparative efficacy of G. candidum encapsulated with alginate (Alg) alone as well as in combination with starch (Alg-S) and xanthan (Alg-X) followed by coated with chitosan (Alg-C, Alg-S-C, Alg-X-C) and nano-chitosan (Alg-CN, Alg-S-CN, Alg-X-CN). Fingerlings of Labeo rohita (15.63 ± 0.35 g) were evenly distributed in ten groups. The control group was fed without probiotics while one experimental group was provided un-encapsulated probiotic (G. candidum QAUGC-01 (1 × 109 CFU g−1)), and other groups were given diet fortified with microcapsules of probiotic prepared with Alg, Alg-S, Alg-X, Alg-C, Alg-S-C, Alg-X-C, Alg-CN, Alg-S-CN and Alg-X-CN. Overall results indicated a significant effect of encapsulated probiotics supplemented diets on growth, feed conversion ratio, enzyme activities, hematology, immunological indices, lipid profile: total cholesterol, high- and low-density lipoprotein and triglyceride content of fish as compared to basal diet devoid of probiotic. Interestingly, chitosan-coated microcapsules of G. candidum supplemented diet groups showed comparatively improved performance as compared to fish fed diet supplemented with uncoated microcapsules. Furthermore, among chitosan-coated microcapsules, Alg-CN microcapsules of G. candidum showed the highest efficiency i.e., the most significant positive effect on all investigated parameters followed by Alg-C microcapsules of G. candidum. Current investigation reveals that the Alginate-nano chitosan encapsulating formulation is the best to improve the viability and target release of locally isolated G. candidum QAUGC-01 in the gastrointestinal tract of L. rohita. Hence, the current investigation suggests a possible way of improving the growth and health status of L. rohita by feeding a diet supplemented with Alg-CN microcapsules of G. candidum. [Display omitted] • Determined the in vivo efficacy of G. candidum microcapsules prepared by different polymers. • Fish showed the best performance in response to Alg-CN microcapsules of probiotic. • Alg-CN appeared as an excellent encapsulating material for the target release of G. candidum. [ABSTRACT FROM AUTHOR]