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In this study, we investigated the feasibility of Ginkgo biloba seeds powder by solid-state fermentation with Eurotium cristatum for developing high-value ginkgo seeds products. The optimum fermentation medium was consisted of 10 g of 40-mesh ginkgo seeds powder loaded in 100 mL Erlenmeyer flask with 50% (w/w) of water content, 4% (w/w) of MgSO4 and 5% (w/w) of KH2PO4 addition. The optimum fermentation conditions were pH 5.0, 2 × 108 CFU/g of inoculum size, 3 mL of sterilized water supplemented every two days during the four days of fermentation. Through fermentation, the spore number of E. cristatum was improved by about 36 times with the production of lovastatin reaching (54.10±0.16) µg/g. The antioxidant activity of fermented ginkgo seeds powder also got obvious enhancement, which could help eliminate excess free radicals produced by normal metabolism. The content of free amino acids increased by 82.32%. Except that the sugar was consumed in some degree, the other nutritional and functional components were well preserved while the content of detrimental ginkgolic acids was reduced by 44.97%. In addition, fermented ginkgo seeds powder possessed better digestibility and showed pleasant orange-like smelling. In conclusion, the quality of ginkgo seeds powder was remarkably improved through solid-state fermentation by using E. cristatum, which could be a promising way for functional applications of ginkgo seeds.

Anthracnose disease caused by Colletotrichum lindemuthianum (Sacc. and Magnus) Lams- -Scrib is one of the most devastating seed-borne diseases of common bean (Phaseolus vulgaris L.). In the present study, we evaluated the antifungal activity of Bunium persicum essential oil (EO) and its main constituents on mycelial growth, sporulation and spore germination inhibition of C. lindemuthianum. The main objective of this study was to investigate the effect of EO and its main constituents on decreasing the activity of cell wall degrading enzymes (CWDEs) produced by C. lindemuthianum, which are associated with disease progress. Also, the effects of seed treatment and foliar application of EO and its main constituent, cuminaldehyde, on anthracnose disease severity was investigated. The essential oil of B. persicum, was obtained by using a clevenger apparatus and its major constituents were identified by gas chromatography-mass spectrometry (GC-MS). The EO was characterized by the presence of major compounds such as cuminaldehyde (37.7%), γ-terpinene (17.1%) and β-pinene (15.4%), which indicated antifungal effects against C. lindemuthianum. This pathogen did not grow in the presence of EO, cuminaldehyde and γ-terpinene, β-pinene at 1,500; 1,010 and 1,835 ppm concentrations, respectively. Also, sporulation and spore germination of C. lindemuthianum was completely inhibited by EO and cuminaldehyde. Synergistic effects of the main constituents showed that combing γ-terpinene with cuminaldehyde induced a synergistic activity against C. lindemuthianum and in combination with β-pinene caused an additive effect. Activities of pectinase, cellulase and xylanase, as main CWDEs, were decreased by EO and its main constituents at low concentration without affecting mycelial growth. Seed treatment and foliar application of peppermint EO and/or cuminaldehyde significantly reduced the development of bean anthracnose. We introduced B. persicum EO and constituents, cuminaldehyde and γ-terpinene, as possible control agents for bean anthracnose.

The study aimed to determine the sterilization effect of a combination of high-pressure thermal sterilization (HPTS) and e-polylysine (PL) on Bacillus subtilis spores. The spores were treated with HPTS (550 MPa at 25°C, 65°C and 75°C) combining with e-PL at 0.1% and 0.3%. The results showed that HPTS and e-PL synergistically inactivated the spores. The increased temperature and e-PL concentration decreased the number of surviving spores, with the maximal inactivation of the spores in the treatment of 550 MPa, 75°C combining with 0.3% e-PL. The increases in the temperature and e-PL concentration significantly increased the release of the intracellular components in the spore suspension, with the maximal value for the spores treated with 550 MPa, 75°C and 0.3% e-PL. The maximal fluidity and permeability of the cell inner membrane were observed in the treatment of 550 MPa, 75°C combining with 0.3% e-PL. Changes in membrane lipids were detected from 3000 to 2800 cm -1 by Fourier transform infrared spectroscopy. The results may provide new insights into the mechanism by which HPTS and e-PL synergistically sterilize Bacillus subtilis spores.

Fusarium moniliforme (F. moniliforme) and its secondary metabolite fumonisin pose a severe threat to food safety, and searching for effective antimicrobial agents is a focus of current research. In this study, the secondary structure of Sub3 was analyzed by circular dichroism, meanwhile, the inhibition rate of Sub3 against F. moniliforme infection of maize was studied. To explore the possible inhibition mechanisms, morphological and structural changes of spores treated with Sub3 at 0, 1/2MIC and MIC were observed by scanning electron microscopy and transmission electron microscopy; the cell wall integrity, membrane integrity, reactive oxygen species, mitochondrial membrane potential, ATP synthase activity, redox reactions, and the nuclear damage of F. moniliforme were also investigated. The results showed that Sub3 was mostly in the state of random in deionized water, while mainly showed the β-sheet structure in the hydrophobic environment of 50% TFE solution, indicating that Sub3 might generate partial structure deformation when acting on the cell membrane; and its minimum inhibitory concentration (MIC) on F. moniliforme spores was 0.2 g/L. Under the 1/2MIC and MIC, the inhibition rates of Sub3 against F. moniliforme infected maize were 34.3% and 75.6%, respectively. The results of inhibition mechanisms revealed that the defective pathogenicity of F. moniliforme caused by Sub3 was attributed to damages on both the cell wall and the cell membrane, which might upset balance of intracellular redox system and mitochondrial energy metabolism and trigger nucleus damage, ultimately leading to cell death. The results provided direct evidence for inhibition of F. moniliforme infection of maize by Sub3, and useful knowledge applicable for food preservation.

Background The global shift toward greener societies demands new technologies and work operations in the waste-management sector. However, progressive industrial methods do not necessarily consider workers’ health. This study characterized workers' exposure to bioaerosols and investigated the bioaerosols’ potential to engage the immune system in vitro. Methods Full shift personal aerosol sampling was conducted over three consecutive days. Dust load was analyzed by gravimetry, fungal and actinobacterial spores were analyzed by scanning electron microscopy, and endotoxin by limulus amebocyte lysate (LAL) assay. In vitro exposure of HEK cells to airborne dust samples was used to investigate the potential of inducing an inflammatory reaction. Results The total dust exposure level exceeded the recommended occupational exposure limit (OEL) of 5.0 mg/m3 in 3 out of 15 samples. The inhalable endotoxin level exceeded the recommended exposure level by a 7-fold, whereas the fungal spore level exceeded the recommended exposure level by an 11-fold. Actinobacterial spores were identified in 8 out of 14 samples. In vitro experiments revealed significant TLR2 activation in 9 out of 14 samples vs. significant TLR4 activation in all samples. Conclusion The present study showed that the dust samples contained potentially health-impairing endotoxin, fungi, and actinobacterial levels. Furthermore, the sampled dust contained microbial components capable of inducing TLR activation and thus have the potential to evoke an inflammatory response in exposed individuals.

Colletotrichum nymphaeae is the dominant species causing anthracnose disease of peach in China. In this study, 140 isolates of C. nymphaeae were assessed for their sensitivity to six fungicides. It was found that C. nymphaeae was highly resistant to carbendazim, procymidone, and boscalid but sensitive to pyraclostrobin and prochloraz. For fludioxonil, the fungus exhibited differential sensitivities (i.e., approximately 14% of isolates were resistant to fludioxonil and the resistance was stable). Fludioxonil-resistant isolates had a mean EC50 value of 2.2380 µg/ml, whereas the mean EC50 value was 0.0194 µg/ml in fludioxonil-sensitive isolates. The mean EC50 values of C. nymphaeae for pyraclostrobin and prochloraz were 0.0083 µg/ml and 0.002 µg/ml, respectively. No cross-resistance was observed between fungicides from different groups. Mycelial growth rate, control efficacy, and osmotic stress responses were significantly different (P < 0.05) between fludioxonil-sensitive (FluS) and -resistant (FluR) isolates, but no significant difference was observed (P > 0.05) in virulence and sporulation between FluS and FluR isolates. No mutation was detected in coding regions of the CnOs-1, Cal, Hk1, Hog1, TPI, and Mrr1 genes. Interestingly, with fludioxonil treatment, the expression of ABC transporter gene atrB was significantly overexpressed in some resistant isolates. However, overexpression of the atrB gene was not detected in one moderately and one highly resistant isolate, indicating that other unknown mechanisms may be involved. Current findings uncovered several effective chemicals and provided the foundation for designing management strategies to practically control peach anthracnose with the most effective demethylation inhibitor fungicides and quinone outside inhibitor fungicides.

Botryosphaeria dothidea causes white rot, which is among the most devastating diseases affecting apple crops globally. In this study, we assessed B. dothidea resistance to carbendazim by collecting samples from warts on the infected branches of apple trees or from fruits exhibiting evidence of white rot. All samples were collected from different orchards in nine provinces of China in 2018 and 2019. In total, 440 B. dothidea isolates were evaluated, of which 19 isolates from three provinces were found to exhibit carbendazim resistance. We additionally explored the fitness and resistance stability of these isolates, revealing that they were no less fit than carbendazim-sensitive isolates in terms of pathogenicity, sporulation, and mycelial growth and that the observed carbendazim resistance was stable. Sequencing of the β-tubulin gene in carbendazim-resistant isolates showed the presence of a substitution at codon 198 (GAG to GCG) that results in an alanine substitution in place of glutamic acid (E198A) in all 19 resistant isolates. A loop-mediated isothermal amplification (LAMP) method was then developed to rapidly and specifically identify this E198A mutation. This LAMP method offers value as a tool for rapidly detecting carbendazim-resistant isolates bearing this E198A mutation and can thus be used for the widespread monitoring of apple crops to detect and control the development of such resistance.

To achieve an economically viable substitutive strategy for lignocellulosic residues use, cellulose degradation by efficient Trichoderma strains become a key alternative. This study aimed to explore the effects of various cultural conditions on the degradation of different lignocellulosic substrates (corn straw and licorice residues) by Trichoderma longibrachiatum and Trichoderma afroharzianum in solid state fermentation. The strains were isolated from the rhizospheric soils of medicinal plants. In addition, the best fermentation combination was selected to evaluate the degradation results. This study confirmed that fermentation conditions and different components of corn straw and licorice residues were both crucial factors affecting the cellulase activity and spore production of two Trichoderma strains. A combination of T. afroharzianum degrading corn straw was selected for Response Surface Methodology optimization. The best fermentation conditions were fermentation time of 5.72 days, initial material liquid ratio of 1:4.58, initial pH of 6.32 and fermentation temperature of 28.8 ℃, with a filter paper cellulase activity of 0.91 U/mL. After continuous fermentation, the spore production reached 6.18 × 109 spores/g, the crude fiber degradation rate reached 23.5% with the reducing sugar content maintained at 11 mg/g. These results highlight the great potential of T. afroharzianum degrading corn straw for organic amendment.

Fusarium graminearum is an important fungus causing a variety of maize diseases, including stalk rot, ear rot, and sheath rot. However, conidia of F. graminearum are not easily obtained under normal culture conditions, which seriously affects the identification and pathogenicity assessment of the isolates and screening of resistance sources. This study was undertaken to develop and utilize a rapid sporulation technique of F. graminearum using liquid cultivation, which could meet the needs of various tests. The results show that the optimum conditions for sporulation of F. graminearum were as follows: culture medium, 0.154 mol/liter of saline; temperature, 28 to 30°C; incubation time, 96 h; initial pH, 9 to 10; illumination, continuous ultraviolet light; and shaking speed, 150 rpm. Using this culture method, conidial concentration of tested F. graminearum strains can reach >1.5 × 105 conidia/ml. Compared with the existing methods using mung bean and carboxylmethyl cellulose as matrix, saline is relatively inexpensive, and the culture process, relatively quick. Overall, this study provided a systematic, rapid, and simple method to obtain a large number of conidia of F. graminearum.

Murray-Darling Freshwater Research CentreMDFRC item.This communication examines the proposal that actinomycete populations, and thus the occurrence of taste and odour problems in potable water supplies, are related to the input of organic matter to reservoirs. The number of actinomycetes in Lake Mulwala, a man-made lake in southeastern Australia, ranged from 2-80 ml-1 in the water column, and 2.7-12 × 104cm-3 in the sediments. Population densities in the water column and sediments were greatest in winter and summer, respectively. They were not highly correlated with protein or polysaccharide degradation. The weak relationship between actinomycete numbers and the rate of organic-matter breakdown was probably due to metabolic inactivity of the bacteria, since actinomycetes in the sediments occurred mainly as spores rather than as vegetative cells. Limiting the input of organic matter, for instance by the removal of fringing vegetation, will have little effect on actinomycete populations in this reservoir.

In semi-arid Mediterranean ecosystems, biotic and abiotic constraints have led to intense forest destruction and ecosystem deterioration and particularly to limitation in the production of Argan tree. Reforestation is thus more than ever a major challenge and an absolute necessity. The use of arbuscular mycorrhizal fungi (AMF) is of great importance in the processes of sustainable regeneration of the vegetation cover, given their roles in the improvement of plant growth and in the protection of soils. In the current study, Argan seedlings were inoculated with five arbuscular mycorrhizal fungi complexes and six arbuscular mycorrhizal fungi monospecific isolates. Growth, nutrition, photosynthetic pigments, and mycorrhizal colonization were under study. The soil samples were obtained from different ecosystems. Trap culture with Maize (Zea mays L.) was used for the production of mycorrhizal inoculum directly for complexes. Monospecific isolates were then produced from spore suspension using the technique of micropipette tips. Germinated seeds of Argan tree were inoculated separately with eleven fungal inoculants, under nursery conditions. Eight-month aged seedlings were compared for their growth and nutritional status. All the considered AMF inoculants stimulated significantly the growth of Argan seedlings; an increase in plant height between 33 and 70% was recorded. The aerial dry weight showed an increase of 62 to 124%, and the root dry weight showed an increase of 24 to 86% compared to the control. Similarly, the mineral contents in inoculated seedlings were significantly increased compared to the control non-inoculated seedlings. The analysis of the chlorophyll contents in leaves showed a significant improvement in inoculated seedlings. In conclusion, this first use of arbuscular mycorrhizal fungi isolates had shown that either complexes or monospecific isolates could improve significantly growth, mineral nutrition, and photosynthesis of Argan seedlings under nursery conditions. Hence, the use of inoculation with suitable consortium from these isolates is a recommended eco-friendly strategy for the restoration of degraded Argan ecosystems.

Aims Previous work showed that Bacillus subtilis dormant spore killing and germination by dodecylamine take place by different mechanisms. This new work aimed to optimize killing of B. subtilis and other Firmicutes spores and to determine the mechanism of the killing. Methods and Results Spores of seven Firmicute species were killed rapidly by dodecylamine under optimal conditions and more slowly by decylamine or tetradecylamine. The killed spores were not recovered by additions to recovery media, and some of the killed spores subsequently germinated, all indicating that dodecylamine-killed spores truly are dead. Spores of two species treated with dodecylamine were more sensitive to killing by a subsequent heat treatment, and spore killing of at least one species was faster with chemically decoated spores. The cores of dodecylamine-killed spores were stained by the nucleic acid stain propidium iodide, and dodecylamine-killed wild-type and germination-deficient spores released their stores of phosphate-containing small molecules. Conclusions This work indicates that dodecylamine is likely a universal sporicide for Firmicute species, and it kills spores by damaging their inner membrane, with attendant loss of this membrane as a permeability barrier. Significance and Impact of the Study There is a significant need for agents that can effectively kill spores of a number of Firmicute species, especially in wide area decontamination. Dodecylamine appears to be a universal sporicide with a novel mechanism of action, and this or some comparable molecule could be useful in wide area spore decontamination.

Thermal processing remains the major technology in food industry while it inevitably destructs sensory, nutrition and functional ingredients of food. In recent years, there has been a growing interest in non-thermal process. Spores are the dormant state of vegetative cells and have unique multilayers structure. A lot of research focused on the inactivation of spores due to its extremely resistance. This review focused on the inactivation effects and mechanisms of spores by non-thermal processing. High-pressure processing inactivated spores by two step pathways. First moderate high pressure induced the germination of spores, and the resistance decreased rapidly. Then the germinated spores inactivated as followed. Some non-thermal techniques such as ultrasound and ultraviolet radiation had synergistic effects and were usually applied as hurdle technologies.

Due to the dissemination of airborne conidia and spores, molds can contaminate various surfaces. In the food industry sector, their presence and development can have health and economic implications. In order to control these undesirable microorganisms, various approaches can be used but the main one relies on the use of disinfectants. The objective of this review is to report the existing studies on the effect of various disinfectant molecules (i.e., sodium hypochlorite, chlorine dioxide, ethanol and other alcohols, hydrogen peroxide, peracetic acid, and quaternary ammonium compounds) on the inactivation of fungal spores. These studies were sorted depending on the targeted fungal species. Noteworthy, in the food industry, four log and three log reductions are required to claim a fungicidal activity for suspension (European Standard 1650, 2019) and surface (European Standard 13697/IN1, 2019) treatments, respectively. Most of the presented studies concerned Penicillium and Aspergillus species (44 and 31% of the literature, respectively). In general, for a given disinfection procedure, ascospores were more resistant than conidia, and Aspergillus conidia were more resistant than Penicillium ones. However, the variability of encountered molds (e.g. species, strains, physiological state) and disinfection procedures (e.g. molecules, concentrations, contact time) affected the efficacy of disinfectants.

Alternaria brassicicola is considered a weak pathogen of tomato in the field, but with a high potential for mycotoxin production in fruit. However, this species belongs to a diverse and closely related group of species (Alternaria with small spores), which often makes their morphological identification and control difficult. In the present research, a molecular identification of tomato Alternaria isolates was made using sequence data of the internal transcribed spacer (ITS) region and the 5.8S ribosomal DNA (rDNA) gene of the isolates. Isolates were identified as Alternaria brassicicola. They were obtained from samples collected from symptomatic tomato leaves in Loumbila, a locality in the Central Plateau region of Burkina Faso. In vitro antifungal tests with essential oils of Cymbopogon nardus and Eucalyptus camaldulensis showed an inhibitory effect of these oils on A. brassicicola. The inhibition rates recorded by the two essential oils at appropriate doses (1, 5, 10, 50 and 100%) are higher than those obtained with the chemical fungicides Azoxystrobin and Mancozeb. The use of formulations based on these essential oils could be an alternative to hazardous pesticide treatments, thus allowing a safer and more ecological management of field diseases and toxins of Alternaria sp. in tomato fruits. Key words: Alternaria brassicicola, molecular identification, biological fungicide.

The antiochratoxigenic (anti-OTA) activity of dichloromethane extract of Macfadyena cynanchoides stems, its antifungal metabolites (lapachol and 1-hydroxy-4-methyl anthraquinone) and sodium metabisulfite was evaluated alone and in combination with this commercial preservative on Aspergillus species at sub-lethal concentrations. Grape juice inoculated with 5×103 spores/mL of A. carbonarius or A. niger was supplemented with the extract (2500 to 156.3 µg/mL), the quinones (1250 to 78.1 µg/mL) or sodium metabisulfite (2500 to 156.3 µg/mL). OTA accumulation was measured in the sub-lethal concentrations after incubating in the dark for 6 days at 15°C. The extract and sodium metabisulfite completely inhibited growth of both fungi at 2500 µg/mL while lapachol and 1H4MA required 1250 µg/mL. Average OTA biosynthesis declined 30-60% respect to control at extract concentrations of 625-1250 µg/mL. Both lapachol and 1H4MA tested at 625 µg/mL exerted a similar anti-OTA effect with an average inhibition of 30%. In the case of sodium metabisulfite, it increased OTA production between 60 to 100% at all the sub-lethal concentrations. Binary mixtures of extract or lapachol or 1H4MA + sodium metabisulfite tested at concentrations of 9.8 + 156.3 µg/mL, 19.5 + 312.5 µg/mL and 39.1 + 625 µg/mL completely inhibited OTA production. In addition, the mixture lapachol + sodium metabisulfite (9.8 + 156.3 µg/mL) delayed a little the time required for completion of the alcoholic fermentation, but did not reduce the Saccharomyces cerevisiae viability or modify physico-chemical parameters measured at the end of the process. Our results show that the mixture sodium metabisulfite + lapachol has potential as an antifungal and anti-OTA agent useful to reduce the doses of sulfites in the control of Aspergillus on post-harvested grapes.

Huperzine-A (HupA) is an emerging, powerful, and promising natural acetylcholinesterase inhibitor. Despite that, the achieved yields of HupA from microbial sources are still far from the industrial applications. Accordingly, this paper was conducted to valorize solid-state fermentation (SSF) as an efficient production platform of HupA. Four agro-industrial wastes, namely rice bran, potato peel, sugarcane bagasse, and wheat bran, were tested and screened as cultural substrates for the production of HupA by the endophytic Alternaria brassica under SSF. Maximum HupA production was attained on using rice bran moistened by Czapex’s dox mineral broth. In the effort to increase the HupA titer, supplementation of the best moistening agent by different carbon and nitrogen sources was successfully investigated. Additionally, factors affecting HupA production under SSF including substrate concentration, moistening level, and inoculum concentration were optimized using response surface methodology. A Box-Behnken design was applied for generating a predictive model of the interactions between these factors. Under the optimum conditions of 15 g rice bran, inoculum concentration of 5 × 106 spores mL−1, and 60% moisture level, HupA concentration was intensified to 518.93 μg g−1. Besides, HupA production by the fungal strain was further enhanced using gamma-irradiation mutagenesis. The final HupA production was significantly intensified following exposure to 0.5 KGy gamma radiation to 1327 μg g−1, which represents a 12.85-fold increase. This is the first report on the successful production of the natural fungal metabolite HupA under SSF. Moreover, the achieved yield in this study using agro-industrial wastes may contribute to reducing the cost of HupA manufacture. Key points • Different agro-industrial by-products were tried as cultural substrates for the production of the acetylcholinesterase inhibitor HupA under SSF for the first time. • Factors affecting HupA production under SSF were optimized using response surface methodology. • The final HupA production was intensified following exposure to gamma radiation recording 1327 μg g −1 , which represents a 12.85-fold increase.

Signaling via volatile organic compounds (VOCs) has historically been studied mostly by entomologists; however, botanists and mycologists are increasingly aware of the physiological potential of chemical communication in the gas phase. Most research to date focuses on the observed effects of VOCs on different organisms such as differential growth or metabolite production. However, with the increased interest in volatile signaling, more researchers are investigating the molecular mechanisms for these effects. Eight-carbon VOCs are among the most prevalent and best-studied fungal volatiles. Therefore, this review emphasizes examples of eight-carbon VOCs affecting plants and fungi. These compounds display different effects that include growth suppression in both plants and fungi, induction of defensive behaviors such as accumulation of mycotoxins, phytohormone signaling cascades, and the inhibition of spore and seed germination. Application of ‘-omics’ and other next-generation sequencing techniques is poised to decipher the mechanistic basis of volatiles in plant–fungal communication.

Interest in phage-based therapeutics is increasing, at least in part due to the need for new treatment options for infections caused by antibiotic-resistant bacteria. It is possible to use wild-type (WT) phages to treat bacterial infections, but it is also possible to modify WT phages to generate therapeutics with improved features. Here, we will discuss features of Phico Therapeutics’ SASPject technology, which modifies phages for use as targetable nano-delivery vehicles (NDV), to introduce antibacterial Small Acid Soluble Spore Protein (SASP) genes into specific target bacteria.

The presence of spore-forming microorganisms and their adhesion to contact surfaces in dairy plants is a major concern because dairy products are prone to cross-contamination. Spore formers and their spores can survive milk processing treatments due to their heat resistance. One source of these spore formers is bacterial biofilms, which grow and accumulate on most surfaces in dairy industrial plants, such as pipes, heat exchangers, pasteurized plates, and storage tanks. Their endospores form biofilms by attaching to these surfaces and germinating when conditions become more favorable. The cross-contamination of dairy products by bacterial biofilms may lead to reduced shelf life and spoilage. To minimize the problem caused by thermoduric bacteria, the dairy industry adopts several approaches. Pasteurization is an irreplaceable technique for milk processing. Unfortunately, some bacteria and endospores are resistant to heat treatment, which can grow and cause spoilage of dairy products. Thus, alternative approaches that could help to reduce microbial counts are needed. In our previous study, we demonstrated the effectiveness of ultrasonication to inactivate spore formers and reduce the overall microbial counts in milk. In the current study, we investigated the recovery of cavitation-induced injured cells during the storage of ultrasonicated skim milk. Three common spore formers—Geobacillus stearothermophilus (ATCC 15952), Bacillus licheniformis (ATCC 6634), and Bacillus sporothermodurans (DSM 10599)—were selected to conduct challenge studies by inoculating skim milk samples and exposing them to ultrasonication (10 min each at 80% amplitude). This treatment was done in an ice bath to control the resultant temperature increase. The ultrasonicated skim milk samples were then held for 1, 2, 4, or 12 h in the refrigerator (4°C) to study the recovery of cells following cavitation-induced injury. Ultrasonication resulted in cell injury, as demonstrated by scanning electron microscopy. The injured cells can potentially recover under appropriate conditions during the storage of ultrasonicated milk and could affect the microbiological quality of milk and products manufactured with such milk. The respective bacterial counts for the 3 organisms in the spiked skim milk, on average, were approximately 6.0 log cfu/mL; immediately after ultrasonication, these counts decreased to 3.50 ± 0.02, 4.38 ± 0.02, and 3.75 ± 0.05 log cfu/mL for G. stearothermophilus, B. licheniformis, and B. sporothermodurans, respectively. During 12 h of subsequent incubation at 4°C, their counts increased to 4.17 ± 0.05, 5.25 ± 0.1, and 5.69 ± 0.06 log cfu/mL, respectively. All experiments were done in triplicate for all 3 bacteria. To conclude, slow recovery of injured cells of spore-forming bacteria is possible in ultrasonicated milk during storage under refrigeration conditions.

Filamentous fungi can enter drinking water supply systems in various ways, and exist in suspended or sessile states which threatens the health of individuals by posing a high risk of invasive infections. In this study, the biofilms formation kinetics of the three genera of fungal spores, Aspergillus niger (A. niger), Penicillium polonicum (P. polonicum) and Trichoderma harzianum (T. harzianum) isolated from the groundwater were reported, as well as the effects of water quality parameters were evaluated. In addition, the efficiency of low- concentrations of chlorine-based disinfectants (chlorine, chlorine dioxide and chloramine) on controlling the formation of fungal biofilms was assessed. The results showed that the biofilms formation of the three genera of fungi could be divided into the following four phases: induction, exponential, stationary and sloughing off. The optimum conditions for fungal biofilms formation were found to be neutral or weakly acidic at 28 °C with rich nutrition. In fact, A. niger, P. polonicum, and T. harzianum were not observed to form mature biofilms in actual groundwater within 120 hr. Carbon was found to have the maximum effect on the fungal biofilms formation in actual groundwater, followed by nitrogen and phosphorus. The resistance of fungal species to disinfectants during the formation of biofilms decreased in the order: A. niger > T. harzianum > P. polonicum. Chlorine dioxide was observed to control the biofilms formation with maximum efficiency, followed by chlorine and chloramine. Consequently, the results of this study will provide a beneficial understanding for the formation and control of fungal biofilms.

One of the most troublesome postharvest diseases of citrus fruits is sour rot, caused by Geotrichum citri-aurantii. Sour rot reduces the shelf life of the fruits leading to massive economic losses. This study investigated the potential for a combination of cinnamaldehyde and citral (CC; 1: 2, v/v) at reducing the incidence of sour rot postharvest and its possible effect on fruit quality. Our findings show that CC could totally inhibit germination of G. citri-aurantii spores, with the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) both being 0.80 mL L(−1). The combination (CC) acted against G. citri-aurantii by targeting the chitin content of the cell wall. Wax + CC (WCC; 1 × MFC) treatment also showed high efficiency in reducing the incidence of sour rot, which was 40% lower than in the control group by day 8 when all the fruits in the latter were rotten. Apart from vitamin c (Vc) content which was higher in the test group than in the control group, WCC treatment did not have any significant effect on the quality of the citrus fruits, the examined fruit quality parameters being weight loss rate, coloration index, firmness, pH, total soluble solid (TSS) content, Vc content, as well as solid acid ratio. These results indicate that the combination of cinnamaldehyde and citral (CC, 1: 2, v/v) can be used as a natural preservative to alleviate the progress of sour rot in citrus fruits postharvest.

A broad-spectrum antimicrobial peptide named Paracin 1.7 was produced by Lactobacillus paracasei HD1.7, which was isolated from Chinese sauerkraut juice. In this study, the influence of cocultivation on the communication mechanism of L. paracasei HD1.7 and Bacillus subtilis was investigated. The two bacterial strains were grown in monoculture and indirect coculture, and the growth of both bacteria and bacteriocin production as well as the transcriptional level of luxS in L. paracasei HD1.7 and spo0A in B. subtilis were monitored. Bacteriocin production and cell numbers were increased significantly when L. paracasei HD1.7 cells were indirectly cocultured with B. subtilis, and bacteriocin-producing L. paracasei HD1.7 can prevent the growth and sporulation of B. subtilis. After indirect coculture with B. subtilis, the expression of luxS in L. paracasei HD1.7 increased in the exponential growth phase and decreased in the stationary phase compared to monoculture. The expression of spo0A in B. subtilis dropped in the indirect coculture compared to the monoculture. It indicate that the upregulation of luxS is due to a response to a secreted compound produced by B. subtilis. The results show L. paracasei HD1.7 has an amensalism on B. subtilis, while B. subtilis has a commensalism on L. paracasei HD1.7.

Grey mould caused by Botrytis cinerea leads to severe economic loss on commercial tomato production. Application of beneficial microorganism offers an eco-friendly alternative for mitigation of tomato fungal disease damage, considering negative influences of fungicides. In the present study, an antagonistic Trichoderma afroharzianum isolate TM24 was evaluated for its biocontrol potential on tomato grey mould. The isolate TM24 showed obviously antagonistic effect on B. cinerea mycelium growth and production of glucanase and chitinase. Leaf spraying with spore suspension of isolate TM24 showed a biocontrol efficiency of over 54% against tomato grey mould in greenhouse pot experiment. The activities of plant defense-related enzymes including polyphenol oxidase, phenylalanine ammonialyase, superoxide dismutase, and peroxidase were all increased to varying degrees in tomato leaves after isolate TM24 treatment. Transcriptome analysis showed that, a total of 1941, 1753 and 38 differentially expressed genes (DEGs) were obtained at 24, 48 and 72 hpi, respectively, in tomato leaves pretreated with T. afroharzianum TM24, and then challenged with B. cinerea inoculation. The DEGs were mainly enriched in MAPK signaling pathway and plant hormones signal transduction pathway. Multiple genes that regulated crucial nodes of defense-related pathways, like flavonoid, phenylpropanoid, jasmonic acid and ethylene metabolisms were also identified, which may have positive correlations with the biocontrol potential of isolate TM24 in tomato plants. These promising results provided valuable information on using T. afroharzianum TM24 as a beneficial biocontrol agent in tomato grey mould management.

The fungus Fusarium oxysporum f. sp. lycopersici (FOL) is known to cause vascular wilt on tomato almost over the world. Inoculation of FOL reduced plant growth and increased wilt of tomato. The following study examined the possible role of arbuscular mycorrhizal fungi (AMF) consortium comprising of Rhizophagus intraradices, Funneliformis mosseae and Claroideoglomus etunicatum against FOL in tomato and explored in an inducing plant systemic defense. AMF inoculation reduced the wilt disease within vascular tissue and in vivo production of fusaric acid was observed which may be responsible in reduced wilting. FOL had an antagonistic effect on AMF colonization, reduced the number of spores, arbuscules and vesicles. AMF also inhibited the damage induced by Fusarium wilt through increasing chlorophyll contents along with the activity of phosphate metabolising enzymes (acid and alkaline phosphatases). Moreover, tomato plants with mycorrhizal inoculation showed an increase in the level of antioxidant enzymes including glutathione reductase, catalase, and etc. with an ultimate influence on the elimination of reactive oxygen species. Moreover, rise in phosphatase along with antioxidant enzymatic systems and enhanced photosynthetic performance contributed to induced resistance against FOL in tomato.

Soluble silica (Si) treatment has been reported to control postharvest fungal diseases and extend shelf life of bananas. In this study, the effects of soluble silica treatment on antifungal activity of fruit peel and direct inhibitory effect against anthracnose and crown rot (CR) pathogens in banana were investigated. Mature banana cv. ‘Embul’ fruits, treated with potassium silicate (1500 μg mL-1 K2SiO3 solution for 20 min) or with water (control) were artificially inoculated with anthracnose pathogen (Colletotrichum sp.) and CR pathogen (Lasiodiplodia sp.), and assessed for anthracnose lesion diameters and CR Index. Bioassays with Cladosporium and Colletotrichum sp. were performed to assess antifungal activity in ethyl acetate extracts of Si treated (Si+) and control (Si-) fruit peel tissues. Total phenolic (TP) contents of Si+ and Si- peel extracts were determined by Folin Ciocalteu assay. To test direct inhibitory effect of Si on growth, the two pathogens were grown in Potato Dextrose Broth (PDB) media amended with silica (0, 500, 1000, 1500 and 2000 μg mL-1) and harvested for mycelial dry weights and spore counts. A significant delay in symptom development and reduction of severity of both diseases was observed in Si+ fruits. In bioassay plates, three antifungal zones (Rf = 0.14, 0.48, 0.79) appeared in both Si+ and Si- extracts, indicating them to be pre-formed antifungal compounds (phytoanticipins). Si+ extracts showed higher antifungal activity and TP levels. Reduction of mycelial growth and spore production was observed with increased Si levels in PDB. Si-enhanced resistance to fungal rots in bananas can be partly attributed to enhanced phytoanticipin levels, including phenolics, and direct inhibitory effect on pathogens.

A large-scale study under controlled conditions was conducted to estimate the influence of diversified level of biotic: Fusarium culmorum and abiotic factors: herbicide (H; sulfosulfuron), fungicides (F1; cyproconazole + propiconazole), (F2; spiroxamine + tebuconazole + triadimenol) and humic biostimulator (B) on the profile of biochemical compounds (6 groups) and mycotoxins (11) in wheat grain. The following experiments were conducted: I: wheat inoculation with F. culmorum spore suspension (OD600 = 0.3; 0.7; 1.3), II: H, III: H+½F1+½F2, IV: H + F1 + F2, V: H + B, VI: H + F1 + F2 + B and VII: B. Multifactorial wheat response to biotic/abiotic stress factors was noted, manifesting in the highest reduction of total soluble carbohydrates (28%; IV) and proteins (34%, VII) related to abiotic factors. The lowest starch concentration was determined in Exp. I (600.54 µg g−1 dm), while the highest was found in control (794 µg g−1 dm). Furthermore, the maximum level of amino acids was observed in Exp II, and of phenolic compounds in Exp. I (894.59 and 933.93 µg g−1 dm, respectively). For the first time, acid phosphatase activity was determined in wheat grain under sulfonylurea, morpholine, triazole and humic biostimulator protection, indicating biostimulator contribution to elevated absorption of assimilable phosphorous forms and improvement of crop nutrition. Total mycotoxins: 3-AcDON, 15-AcDON, DON, NIV were the highest in inoculated wheat (Exp. I, 2063.9 µg kg−1). The most effective protection and the lowest concentration of mycotoxins was achieved in Exp. VI (155.3 µg kg−1, 67% reduction compared to control). Our study indicated that chemical treatments enriched by humic biostimulator could be implemented in the integrated program of wheat protection in agricultural practice.

Surfaces can be contaminated by droplets produced through coughing or sneezing. In this exploratory work, the UV disinfection results of Bacillus subtilis spores in dried saliva droplets were fitted to a three-parameter kinetic model (R2 ≥ 0.97). This model has a disinfection rate constant for single organisms and a smaller one for aggregates found in droplets. The fraction of organisms found in aggregates (β) could account for the effects of different-sized droplets in the experimental work. Since a wide spectrum of droplet sizes can be produced, and some of the rate constants were uncertain, Monte Carlo simulation was used to estimate the UV inactivation performance in dried saliva droplets in a variety of conditions. Using conservative distribution for β, the model was applied to the UV disinfection of SARS-CoV-2 in dried saliva droplets. It was shown that a one-log reduction of SARS-CoV-2 was very likely (p>99.9%) and a two-log reduction was probable (p=75%) at a dose of 60 mJ/cm2. Aggregates tend to be variable and limit the log reductions that can be achieved at high UV doses.

Lavender essential oil (LEO), a natural antimicrobial agent, is generally recognized as safe and effective in the inhibition of phytopathogenic fungi. Direct contact and fumigation (in vivo and in vitro) were used to study the fungistatic effect of LEO on Monilinia fructicola. Additionally, the effect on the ultrastructure of cells and the degree of destruction of the cell membrane of M. fructicola were revealed. In addition, the effects of LEO on the expression levels of apoptosis-related genes in M. fructicola cells were detected, and GC-MS was used to analyze the main components of LEO. LEO had a good inhibitory efficacy against M. fructicola in flat peaches, with almost complete growth inhibition at 800 μL/L. These effects were associated with the leakage of cytoplasmic contents, hyphal distortion, and spore disruption. Moreover, the expression of apoptosis RTG1 and RLM1 genes increased with LEO treatment. These results demonstrate that LEO can inhibit M. fructicola by inducing cytoplasmic membrane damage and cell apoptosis in fungi, and that the major ingredients of LEO are monoterpenes and sesquiterpenes, which are presumed to contribute to the inhibitory effects.

Mycoremediation is an important process that targets the removal of petroleum hydrocarbons by fungi. Fungi have advantages with their extensive enzymatic systems, rapid adaptation to toxic organic pollutants, and to adverse environmental conditions. In this study, the colorimetric method was used for the preliminary investigation of petroleum degradation with ten fungal strains. Petroleum degradation ability of spore suspension, live biomass (fungal pellet and disc) and cell-free culture supernatant of the potent A. ochraceus strain were investigated by gravimetric analysis. It was found that the fungal disc (94%) was more successful than the spore suspension (87%) in petroleum degradation under physiological conditions determined as pH:5.0, 1% of petroleum concentration, 5% (v/v) of inoculum concentration (with spore suspension) and 1 g/100 mL of inoculum amount (with fungal disc) and 7 days of the incubation period. The degradation rate constant and half-life period of spore suspension were calculated as 0.291 day−1 and t1/2 = 0.340 and of the fungal disc were 0.401 day−1 and t1/2 = 0.247. Although, 7.5% and 10% (v/v) concentration of cell-free culture supernatant achieved more than 80% petroleum removal, it was not as effective as a fungal disc. According to gas chromatography/mass spectrometry analysis, the fungal disc of A. ochraceus strain degraded long-chain n-alkanes such as C35 and C36 more effectively than n-alkanes in the range of C22–C34. The fact that the A. ochraceus NRRL 3174 strain has a high petroleum degradation capacity as well as being a potent biosurfactant producer will provide a different perspective to advanced mycoremediation studies.

Bamboo is a type of plant that grows in Indonesia. So far, people only use the stems and throw away the leaves. As a result, these abundant bamboo leaves become waste. Bamboo leaf waste contains lignin content of 19.8-26.6%, and becomes compost in the long term. The process of composting bamboo leaf litter can be accelerated using an activator such as the inoculum fungi Geotrichum sp. which is ligninolytic so that it can break down lignin complex compounds contained in bamboo leaf waste into simpler compounds. Sorghum contains about 6.5-7.9% fiber. The high fiber content in sorghum seeds can be used as a growth medium for fungal inoculum. The purpose of this study was to determine the effect of sorghum as an inoculum medium for Geotrichum sp. and the effect of inoculum on compost quality. This research was carried out in August - December 2019 at the Microbiology Laboratory of the Biology Department, Faculty of Mathematics and Natural Sciences, Unila. This study used a completely randomized design (CRD) method with 4 treatments, namely Control (Bamboo leaf litter), P1 (Bamboo leaf litter + 1% inoculum), P2 (Bamboo leaf litter + 1.5 % inoculum) and P3 (Bamboo leaf litter). + 2% inoculum) each treatment was repeated 3 times. The variables observed were the number of spores and spore viability using the Colony Forming Unit (CFU) calculation on inoculum and compost. Analysis of the content of C, N, P, and C/N ratio was carried out to determine the quality of the compost. Based on the research results, sorghum can be used as a growth medium for the ligninolytic fungi inoculum Geotrichum sp. with spore viability of 74.18% and the addition of 1.5% inoculum (P2) gave the best results on the quality of bamboo leaf compost (Bambusa sp.)

Nosema ceranae, es un parásito obligatorio del intestino medio de las abejas melíferas que causa destrucción de las células epiteliales afectando la digestión y asimilación del alimento, impactando negativamente el desarrollo y sobrevivencia de las colonias de abejas. Con la finalidad de reducir los efectos negativos, se evaluó la eficacia del timol en el control de esta parasitosis. El estudio se realizó en dos apiarios experimentales con un total de 56 colonias de abejas distribuidas en tres grupos experimentales: G1) 18 colonias que recibieron tratamiento con fumagilina como producto de referencia (25.2 mg de fumagilina/semana); G2) 19 colonias que recibieron tratamiento con timol como producto alternativo (66 mg de cristales/semana) y G3) 19 colonias que no recibieron ningún tratamiento (grupo testigo). Los tratamientos con la fumagilina y timol se aplicaron a través del jarabe de azúcar una vez por semana durante cuatro semanas consecutivas. Los niveles de infección de N. ceranae se estimaron en el macerado del abdomen de 60 abejas adultas colectadas de cada colonia experimental. Los resultados al final de los tratamientos indican que las colonias que recibieron fumagilina (G1) disminuyeron sus niveles de infección de 123,529 a 1,805 esporas por abeja; para G2 (timol), la reducción fue de 133,438 a 28,099 esporas por abeja, y para las colonias del grupo testigo (G3) fue de 119,306 a 36,447 esporas por abeja. Los tres grupos experimentales presentaron diferencias estadísticas significativas en los niveles de infección de N. ceranae al final de los tratamientos. La fumagilina presentó una mayor eficacia (95.2 %) en comparación con el timol la, cual fue baja (31.1 % de eficacia) indicando que se requieren estudios adicionales para determinar la concentración más efectiva a nivel de colonia bajo condiciones tropicales de Yucatán, a fin de que este aceite esencial de origen vegetal sea incorporado como producto alternativo para el control de esta parasitosis.

Heat treatment is one of the most widely used processing technologies in the dairy industry. Its primary purpose is to destroy microorganisms, both pathogenic and spoilage, to ensure the product is safe and has a reasonable shelf life. In this study microwave volumetric heating (MVH) was compared with a conventional tubular heat exchanger (THE), in terms of the effects of each at a range of temperatures (75°C, 85°C, 95°C, 105°C, 115°C, and 125°C) on indigenous microflora viability and the germination of inoculated Bacillus licheniformis endospores in reconstituted skim milk. To assess the heat treatment-related effects on microbial viability, classical agar-based tests were applied to obtain the counts of 4 various microbiological groups including total bacterial, thermophilic bacterial, mesophilic aerobic bacterial endospore, and thermophilic aerobic bacterial endospore counts, and additional novel insights into cell permeability and spore germination profiles post-heat treatment were obtained using real-time flow cytometry (FC) methods. No significant differences in the plate counts of the indigenous microorganisms tested, the plate counts of the inoculated B. licheniformis, or the relative percentage of germinating endospores were observed between MVH- and THE-treated samples, at equal temperatures in the range specified above, indicating that both methods inactivated inoculated endospores to a similar degree (up to 70% as measured by FC and 5 log reduction as measured by plate counting for some treatments of inoculated endospores). Furthermore, increased cell permeability of indigenous microflora was observed by FC after MVH compared with THE treatment of uninoculated skim milk, which was reflected in lower total bacterial count at a treatment temperature of 105°C. This work demonstrates the utility of FC as a rapid method for assessing cell viability and spore inactivation for postthermal processing in dairy products and overall provides evidence that MVH is at least as effective at eliminating native microflora and inoculated B. licheniformis endospores as THE.

The exploration of arbuscular mycorrhiza fungi from sugarcane plantation in marginal land in South Sulawesi was carried out to find the source of inoculums showing effective infection. Soil samples were taken from four area with different characteristic of marginal land, namely land with low organic matter content, clay texture, limited irrigation, and undulating land. Mycorrhizae contained in the soil samples were then observed, and the spores obtained were used as the source of isolation by a single spore culture. The mycorrhizal spores were isolated by wet sieving and centrifugation method with 48% sucrose, which were observed under a compound microscope for spore details (100-1000x). Sugarcane root samples were taken to observe mycorrhizal infection in sugarcane root tissue by root staining method. The results of the study showed that the greatest diversity of mycorrhizal genera was found in soil samples of Jambua Block (Glomus, Gigaspora, and Sclerocistis) and AJ-5 Block area (Glomus, Acaulospora, and Sclerocistis). Single-spore isolates obtained were Glomus sp. and Acaulospora sp. Infection test result on four sugarcane varieties commonly grown in Takalar Sugar Factory showed that infectivity of mycorrhizal isolate of Acaulospora sp. was the highest (75%) and significantly different (LSD’test, p 0,05) compared to that of Glomus sp. (66%).

Bacillus subtilis is a commonly used commercial specie with broad applications in the fields of bioengineering and biotechnology. B. subtilis is capable of producing both biofilms and spores. Biofilms are matrix-encased multicellular communities that comprise various components including exopolysaccharides, proteins, extracellular DNA, and poly-γ-glutamic acid. These biofilms resist environmental conditions such as oxidative stress and hence have applications in bioremediation technologies. Furthermore, biofilms and spores can be engineered through biotechnological techniques for environmentally-friendly and safe production of bio-products such as enzymes. The ability to withstand with harsh conditions and producing spores makes Bacillus a suitable candidate for surface display technology. In recent years, the spores of such specie are widely used as it is generally regarded as safe to use. Advances in synthetic biology have enabled the reprogramming of biofilms to improve their functions and enhance the production of value-added products. Globally, there is increased interest in the production of engineered biosensors, biocatalysts, and biomaterials. The elastic modulus and gel properties of B. subtilis biofilms have been utilized to develop living materials. This review outlines the formation of B. subtilis biofilms and spores. Biotechnological engineering processes and their increasing application in bioremediation and biocatalysis, as well as the future directions of B. subtilis biofilm engineering, are discussed. Furthermore, the ability of B. subtilis biofilms and spores to fabricate functional living materials with self-regenerating, self-regulating and environmentally responsive characteristics has been summarized. This review aims to resume advances in biological engineering of B. subtilis biofilms and spores and their applications.

The harm of Aspergillus flavus (A. flavus) and aflatoxin is a severe food safety problem worldwide, which causes huge economic losses every year. Therefore, it is urgent to control the growth of A. flavus and the biosynthesis of aflatoxin. Plant-derived natural compounds are superior to synthetic fungicide in inhibiting the growth of A. flavus benefiting from their high safety to the environment, humans and stock, and low cost. This study aimed to evaluate the antifungal effects and potential antifungal mechanisms of three plant-derived compounds (octanal, nonanal and decanal) against A. flavus. We determined the minimum inhibitory concentrations (MICs) and action mechanism of the three volatile aldehydes on A. flavus and also performed calcofluor white (CW) staining for visualizing the distribution of septa. Cell respiration metabolism and the pathogenicity on maize kernels were also carried out to evaluate the efficacy of the three volatile aldehydes on the growth of A. flavus. The results showed that the three volatile aldehydes could inhibit the germination of spores and mycelial growth of A. flavus, the MICs on spores and mycelia were: octanal (1.0 and 0.5 μL/mL), nonanal (0.5 and 2.0 μL/mL), and decanal (1 and 5 μL/mL). The three volatile aldehydes could strongly damage the integrity of both the cell wall and the cell membrane of A. flavus. Meanwhile, they could decrease the content of total lipid and inhibit respiration metabolism of A. flavus cell. Results of in vitro antifungal test showed that all the three volatile aldehydes could effectively prevent the growth of A. flavus on maize kernels. The study revealed that octanal, nonanal and decanal could effectively inhibit the growth of A. flavus both in culture medium and on maize kernels to different extent. The results confirmed that the plant-derived compounds could be developed into promising antifungal agents applied in the preservation of grains. This study provides a theoretical basis for the research and application of potential antifungal agents.

The results are presented of a comparative study of the sporicidal activity of alcohol sols of nanoparticles of titanium, copper, zinc and tantalum metals in the course of their interaction with a rehydrated lyophilized culture of spores of the vaccine strain Bacillus anthracis STI-1 with the loss of the ability of spores to germinate in nutrient media under optimal conditions using bacteriology and electronic microscopy. The most pronounced sporicidal effect is observed when titanium alcohol sol is exposed to spores. At the same time, spores of B. anthracis STI-1 in titanium alcohol sol are affected by ethyl alcohol, which causes dehydration and denaturation of the protein, the antiseptic cetylpyridinium chloride as a surfactant, which is also a strong electrophilic agent that destroys the exosporium and spore shells, and titanium nanoparticles, which, due to the high surface energy when exposed to spores, cause their pronounced massive adhesion. In addition, titanium nanoparticles, the zeta (? -) value of the potential of which is -44.5 mV, cause a stable energy state of the dispersed system of alcohol sol, which acts as a biocatalyst for intracellular enzymes, causing the hydrolysis of polymer structures of the spore shells and cortex, as well as destroyed nucleoid – an area of spores containing structured genetic material. Spores that do not have a nucleoid in electron microscopy acquire the form of "shadows". As a result of the action of titanium alcohol sol, the activation of germination and the formation of the so-called "metabolic" spores, from which the vegetative cells of B. anthracis STI-1 should have been formed, are prevented. The reason for the high sporicidal efficiency of the alcohol sol of titanium nanoparticles is associated both with the structure and properties and with the technology of synthesis of titanium nanoparticles in the low-temperature plasma zone with the formation, due to the excess of the surfactant cetylpyridinium chloride, of a two-layer shell around the metal nanoparticles, which leads to their "conservation" until the moment of contact with spores and a sharp slowdown in their oxidation in the aquatic environment. The destruction of the formed two-layer shell of metal nanoparticles begins with contact with spores with the simultaneous onset of the formation of titanium ions from the phase of nanoparticles, which actively destroy chemically the shells of the spores. Keywords: microorganisms, Bacillus anthracis STI-1, spores, metal nanoparticles, zeta potential, disinfectant compositions, sporicidal activity.

Wheat blast caused by the hemibiotroph fungal pathogen Magnaporthe oryzae Triticum (MoT) pathotype is a destructive disease of wheat in South America, Bangladesh and Zambia. This study aimed to determine and compare the activities of antioxidant enzymes in susceptible (wheat, maize, barley and swamp rice grass) and resistant (rice) plants when interacting with MoT. The activities of reactive oxygen species-detoxifying enzymes; catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione S-transferase (GST), peroxidase (POX) were increased in all plants in response to MoT inoculation with a few exceptions. Interestingly, an early and very high activity of CAT was observed within 24 h after inoculation in wheat, barley, maize and swamp rice grass with lower H2O2 concentration. In contrast, an early and high accumulation of H2O2 was observed in rice at 48 hai with little CAT activity only at a later stage of MoT inoculation. The activities of APX, GST and POD were also high at an early stage of infection in rice. However, these enzymes activities were very high at a later stage in wheat, barley, maize and swamp rice grass. The activity of GPX gradually decreased with the increase of time in rice. Taken together, our results suggest that late and early inductions of most of the antioxidant enzyme activities occurs in susceptible and resistant plants, respectively. This study demonstrates some insights into physiological responses of host and non-host plants when interacting with the devastating wheat blast fungus MoT, which could be useful for developing blast resistant wheat.

Introduction: Ionized hydrogen peroxide (iHP) is a new technology used for the decontamination of surfaces or laboratory areas. It utilizes a low concentration of hydrogen peroxide (H2O2) mixed wit...

Ganoderma lucidum (GL), also known as Reishi or Lingzhi, is a medicinal mushroom widely used in traditional and folk medicines. The extracts made from the fruiting body and spore of naturally grown GL are the most frequently used in commercial products. More than 400 compounds have been identified in GL with the triterpenoids considered to be the major active components. Large variations in the chemical components were reported in previous studies and there is no comprehensive study of the content of multiple major triterpenoids in the GL product. In addition, there is no report in the comparison of chemical profiles in different parts of GL (i.e., fruiting body and spore). Determining the chemical composition and comparing the differences between fruiting body and spore are essential for the identity, efficacy and safety of various GL products. In this study, 13 compounds (ganoderenic Acid C, ganoderic Acid C2, ganoderic Acid G, ganoderic Acid B, ganoderenic Acid B, ganoderic Acid A, ganoderic Acid H, ganoderenic Acid D, ganoderic Acid D, ganoderic Acid F, ganoderic Acid DM, ganoderol A, and ergosterol) were selected as the chemical markers. The purpose of this study is to develop an HPLC-DAD fingerprint method for quantification of these active components in GL (spore and fruiting body) and test the feasibility of using the HPLC-DAD fingerprint for quality control or identity determination of GL products. The results showed that this method could determine the levels of the major components accurately and precisely. Among the 13 components, 11 ganoderma acids were identified to be proper chemical markers for quality control of GL products, while ganoderal A was in a very low amount and ergosterol was not a specific marker in GL. The extracts of fruiting body contained more chemical compounds than those of spore, indicating that these 11 compounds could be a better chemical marker for the fruiting body than the spore. The HPLC chemical fingerprint analysis showed higher variability in the quality of GL harvest in different years, while lesser variation in batches harvested in the same year. In conclusion, an HPLC assay detecting 11 major active components and a fingerprinting method was successfully established and validated to be feasible for quality control of most commercial GL products.

Anthracnose of grapes inflicted by Sphaceloma ampelinum (de Bary) is widespread and the most destructive disease of grapes (Vitis vinifera L.) worldwide. The pathogen produced irregular, whitish glabrous raised colony which later turned brownish white and developed concentric rings. Acervulus (62.05–79.01 μm) developed in concentric rings were light brown, round to flask shaped bearing hyaline to greenish, guttulated, circular to oblong conidia (5.19 × 2.97 µm) after 20 days of incubation at 28 ± 2 °C. To confirm the morphological identification, the rDNA of isolated pathogen was amplified with 18 s RNA primers to give the expected amplicon of 500 bp.The best culture media for surface mycelium growth was oat meal agar and corn meal agar was found as best media for sporulation of the pathogen. Whereas, maximum mycelia growth and sporulation was achieved at pH 6.5 and temperature of 25–30 °C. Among the bio-control agents screened, Trichoderma harzianum, exhibited maximum inhibition in mycelial growth whereas, among the new fungicides tested, combination of systemic fungicides viz., carbendazim (25%) + flusilazole (12.5%) 37.5 SC @ 0.1%, carbendazim (12%) + mancozeb (63%) 75 WP @ 0.25% and metiram (55%) + pyraclostrobin (5%) @ 0.1% proved effective for the management of the disease.

Quaternary palynology commonly requires the use of acids such as hydrofluoric acid (HF), sulphuric acid (H2SO4), and hydrochloric acid (HCl) to extract pollen grains and spores. In some countries, ...

Sour rot caused by Geotrichum citri-aurantii is a serious postharvest disease of citrus that can result in devastating economic losses. In this study, a new bacterial strain, WE-3, was isolated from soil samples of orchards at Huazhong Agricultural University and then screened in vitro to investigate its antifungal activity against G. citri-aurantii. Bacterium WE-3 was characterized as a member of the Bacillus family by physiological, biochemical, and 16S ribosomal gene analyses. The culture filtrate from strain WE-3 could effectively restrain the expansion of G. citri-aurantii in citrus after 6 d of artificial inoculation. Scanning electron microscopy examination showed that the WE-3 culture filtrate-treated G. citri-aurantii spores were morphologically longer and smoother. The expression of two chitin synthase-related genes and a redox-related gene remained downregulated when G. citri-aurantii was incubated with the WE-3 culture filtrate. Meanwhile, cellular content leakage was accompanied by cell vacuolation of the culture filtrate-treated G. citri-aurantii cells upon transmission electron microscopy examination. Finally, culture filtrate-handled citrus fruit exhibited similar physiological qualities to distilled water-handled fruit. Our study reveals that bacterial strain WE-3 might be a potent biological control agent against G. citri-aurantii in citrus.

Fungal cell wall synthesizing enzymes or remodeling enzymes represent key factors for the interaction of plant pathogen and antifungal agents, which are regarded as potential biocontrol agents. In this study, a novel endo-β-1,3-glucanase from Magnaporthe oryzae was expressed and characterized. The expression of MoGluB was significantly upregulated after 2 days of liquid culture and 48 h after infection, indicating that it may be involved in cell wall reconstitution. Purified MoGluB exhibited high activity on insoluble β-glucans, with a specific activity of 8.18 U/mg toward yeast glucan at pH 9.0 and 50 °C. MoGluB hydrolyzed pachymaran and yeast glucan into oligosaccharides dominated by laminaripentaose, suggesting that it is an endo-β-1,3-glucanase. Incubation of 8 μg of MoGluB with 106 spores/mL resulted in the inhibition of conidial germination and appressorium formation of M. oryzae, illustrating effective biocontrol activity. Hydrolysates of pachymaran induced the expression of defense genes restricting M. oryzae infection in rice plants, indicating an immunostimulatory effect of MoGluB hydrolysates.