Utilization of winery wastes for Trichoderma viride biocontrol agent production by solid state fermentation

Solid-state fermentation in an earthen vessel: Trichoderma viride spore-based biopesticide production using corn cobs

The present study reports the production of Trichoderma viride spores in an earthen vessel using corn cobs. Using 4 kg of corn cobs, spore-based biopesticide was produced after 21 d with a maximum spore count of 2.50 × 109 spores/g of substrate and a moisture reduction from 70.80% w/v to 8.10% w/v. The gas chromatography-mass spectrometry analysis of its ethyl acetate extract revealed that it had 20 secondary metabolites, of which 13 were known to be antimicrobial, one was plant growth-promoting, and one performed both functions. Dried extract dissolved in methanol showed the minimum fungicidal concentration of 5-10 mg/ml against Rhizoctonia solani on potato dextrose agar plate. Plate assays and pot experiments on Rhizoctonia solani-infected potato plants exhibited good antifungal and plant growth-promoting activities. The biopesticide showed 71.28% viability over 10 m of storage in the same earthen vessel at 30 ± 2 °C. Thus, a simple, robust technology was developed with good potential for farm deployment.

Using bibliometrics to analyze the state of art of pesticide use in vineyard agrosystems: a review

The production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region. However, to control pests and regulate wine growth, the extensive use of pesticides is common. The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds. The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review, the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine, i.e., Spain, France, and Italy, are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as follows: soil-plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France, and Italy work the most on developing sustainable alternatives for agricultural practices; however, sustainable alternatives and practices were also the least developed thematic in general.

Control strategies for biofilm control in reclaimed water distribution systems from the perspective of microbial antagonism and electrochemistry

Biofilm formation in reclaimed water (RW) distribution systems presents significant technical challenges to RW utilization. Two main technologies to control biofilm formation, microbial antagonism (MA) and electrochemical oxidation (EO), are not yet widely used in drip irrigation systems (DIS) and their mechanisms of action need further clarification. In this study, we first showed that the MA and EO treatments reduced biofilm formation by about 62% and 68%, respectively, and extracellular polymeric substance (EPS) content by 14% and 49%, respectively, in biofilms compared with raw RW type 1 (R-RW1) in unused pipes, thus effectively improving the performance of DIS. When MA-RW and EO-RW were applied to already clogged systems, the degree of clogging alleviation varied depending on the severity of the original clogging. We recommend adding the antagonist, Bacillus subtilis, to RW at 25% clogging for the maximum effect and to slow the microbial adaptation process. Compared to MA, the recovery effect of EO was slower initially but lasted longer and had a significantly better alleviating effect on severely clogged pipelines. Illumina Mi-SEQ high-throughput sequencing data showed that both MA and EO resulted in a significant decrease in microbial diversity, dynamic changes in bacterial community structure, and disruption of network interaction and network modularity. Meanwhile, both treatments promoted the growth of specific microorganisms, enhanced the interaction between certain microbial components, and improved the efficiency of information, matter, and energy exchange within the modules. In summary, we verified the dredging effect of two strategies on DIS under different water conditions, revealed the differences in their mechanisms of action, and proposed their application scenarios. Our results will help improve the efficiency of RW in agricultural drip irrigation systems and effectively reduce maintenance costs.

Increasing Value of Winery Residues through Integrated Biorefinery Processes: A Review

The wine industry is one of the most relevant socio-economic activities in Europe. However, this industry represents a growing problem with negative effects on the environment since it produces large quantities of residues that need appropriate valorization or management. From the perspective of biorefinery and circular economy, the winery residues show high potential to be used for the formulation of new products. Due to the substantial quantities of phenolic compounds, flavonoids, and anthocyanins with high antioxidant potential in their matrix, these residues can be exploited by extracting bioactive compounds before using the remaining biomass for energy purposes or for producing fertilizers. Currently, there is an emphasis on the use of new and greener technologies in order to recover bioactive molecules from solid and liquid winery residues. Once the bio compounds are recovered, the remaining residues can be used for the production of energy through bioprocesses (biogas, bioethanol, bio-oil), thermal processes (pyrolysis, gasification combustion), or biofertilizers (compost), according to the biorefinery concept. This review mainly focuses on the discussion of the feasibility of the application of the biorefinery concept for winery residues. The transition from the lab-scale to the industrial-scale of the different technologies is still lacking and urgent in this sector.

Evaluation of ultrasound waves for the production of chitinase and β-1,3 glucanase by Trichoderma harzianum through SSF

Cell wall degrading enzymes (chitinase and β-1,3-glucanase) were produced by solid-state fermentation (SSF) using the fungus Trichoderma harzianum and different agro-industrial products, mainly residues. The influence of temperature (25-35 °C), initial moisture content (50-90% w/w), nutrient solution (1-2% v/w), and yeast extract (1-2% w/w) on enzyme activity was evaluated. The application of ultrasound during fermentation for different times (0-6 h/day) was also studied. White rice was the substrate that showed the highest chitinase and β-1,3-glucanase activities, which were 31.31 U/g for chitinase and 23.83 U/g for β-1,3-glucanase after 10 days of fermentation. Application of ultrasound waves during fermentation positively affected (p < 0.05) the enzyme activities. The best results for chitinase (51.88 U/g) and β-1,3-glucanase (39.22 U/g) were obtained with a 50% (w/w) moisture content and 4 h/day ultrasound application for 10 days of fermentation. Increases of 3.6-fold (from 14.37 to 51.88 U/g) and 3.8-fold (from 10.22 to 39.22 U/g) in activities for chitinase and β-1,3-glucanase, respectively, compared to non-sonicated fermentation, were obtained. Ultrasound technique associated with the SSF process was a promising alternative to increase the production activity of cell wall degrading enzymes: chitinase and β-1,3-glucanase.

Soil response to root-knot nematode management with wine vinasse in a solarised horticultural soil under glasshouse conditions

The increasing interest in agroecological practices and the current consideration of agrarian soils as a sustainable resource are driving the development of new strategies to manage soil parasites and diseases. The application of organic matter from different sources to reduce plant parasites contributes to circular economy by applying by-products as soil organic amendments that reduce wastes. Wine vinasse (WV) is a by-product generated to obtain alcohol from wine by physical methods in distilleries. The aim of this study was to determine the potential of WV and its combination with animal manure (WV+M) as soil biodisinfestation products. For this, it was compared with a plastic-covered control to distinguish the biodisinfestation from solarisation effect. The crops tested consisted of a tomato-Swiss chard rotation under glasshouse conditions. Their effects on Meloidogyne incognita, soil fertility, nematode community and crop yield were assessed. The results obtained after two seasons showed a reduction of M. incognita galling in the root system of both crops. The immediate effect after the treatment application was a reduction in the abundance of nematodes and changes in the nematode-based indices that affected all plots, including the control, most likely related to the tillage effect for the treatments application and the plastic cover. Soil fertility was improved by the application of WV (NO3−, Bioav. P) and WV+M (C, Ntotal, K), which reduced herbivore nematode metabolic footprints and enhanced bacterivore footprints. Our results indicate that the combination WV+M was effective reducing M. incognita infection, and improved crop yield. Use of by-products such as WV is a helpful tool for managing horticultural soils.

Anaerobic co-digestion of winery waste: comparative assessment of grape marc waste and lees derived from organic crops

Grapes are one the world's leading fruit crops, with close to 77 million tonnes harvested per year. Grapes are commonly used to produce wine; a process which generates different wastes such as grape mark waste (skins, seeds and stalks), lees and other residues. This study evaluates the treatment of winery waste derived from ecological cultivation by anaerobic digestion to produce energy in the form of methane. Grape marc waste, Verdejo and Pedro Ximenez (PX) wine lees were digested under stable conditions at mesophilic conditions. The PX lees showed the highest methane yield production (433 L_STP CH₄/kg VS) with a maximum OLR of 4.58 kg VS/m³·d. In the evaluated range the process was stable with a range of biodegradability of 51-79%. Due to different types of winery waste are generated at consecutive stages of the main production process, the sequential treatment of PX lees, Verdejo lees and grape marc waste in the same anaerobic digester could be an interesting option. This procedure would facilitate the management of the residual streams generated in wineries during the year and promotes the circular economy in the Montilla-Moriles Protected Designation of Origin.

Fermentation Strategies to Improve Soil Bio-Inoculant Production and Quality

The application of plant beneficial microorganisms has been widely accepted as an efficient alternative to chemical fertilizers and pesticides. Isolation and selection of efficient microorganisms, their characterization and testing in soil-plant systems are well studied. However, the production stage and formulation of the final products are not in the focus of the research, which affects the achievement of stable and consistent results in the field. Recent analysis of the field of plant beneficial microorganisms suggests a more integrated view on soil inoculants with a special emphasis on the inoculant production process, including fermentation, formulation, processes, and additives. This mini-review describes the different groups of fermentation processes and their characteristics, bearing in mind different factors, both nutritional and operational, which affect the biomass/spores yield and microbial metabolite activity. The characteristics of the final products of fermentation process optimization strategies determine further steps of development of the microbial inoculants. Submerged liquid and solid-state fermentation processes, fed-batch operations, immobilized cell systems, and production of arbuscular mycorrhiza are presented and their advantages and disadvantages are discussed. Recommendations for further development of the fermentation strategies for biofertilizer production are also considered.

Impact of antagonistic yeasts from wine grapes on growth and mycotoxin production by Alternaria alternata

AIMS

Alternaria alternata is a major contaminant of wine grapes, meaning a health risk for wine consumers due to the accumulation of toxic metabolites. To develop a successful biofungicide, the effectiveness of epiphytic wine grape yeasts against A. alternata growth and toxin production was assessed in vitro under temperature and a_W conditions that simulate those present in the field.

METHODS AND RESULTS

The effect of 14 antagonistic yeasts was evaluated on growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production by three A. alternata strains in a synthetic medium with composition similar to grape (SN) at three temperatures (15, 25 and 30°C). All Metschnikowia sp. yeast strains evaluated completely prevented A. alternata growth and mycotoxin production at all temperatures in SN medium. Meanwhile, the growth inhibition exerted by Starmerella bacillaris yeast strains was higher at 30°C, followed by 25 and 15°C, being able to show a stimulating or inhibiting effect. Hanseniaspora uvarum yeast strains showed a growth promoting activity higher at 15°C, followed by 25 and 30°C. Even at conditions where A. alternata growth was stimulated by the S. bacillaris and H. uvarum yeasts, high inhibitions of mycotoxin production (AOH, AME and TA) were observed, indicating a complex interaction between growth and mycotoxin production.

CONCLUSION

There is a significant influence of temperature on the effectiveness of biocontrol against A. alternata growth and mycotoxin production. Metschnikowia sp. strains are good candidates to compose a biofungicide against A. alternata.

SIGNIFICANCE AND IMPACT OF THE STUDY

Among the different antagonistic yeasts evaluated, only Metschnikowia sp. strains were equally effective reducing A. alternata growth and mycotoxin at different temperatures underlining the importance of considering environmental factors in the selection of the antagonists.

Integrated biorefinery approach to valorize winery waste: A review from waste to energy perspectives

The ever-increasing environmental crisis, depleting natural resources, and uncertainties in fossil fuel availability have rekindled researchers' attention to develop green and environmentally friendlier strategies. In this context, a biorefinery approach with a zero-waste theme has stepped-up as the method of choice for sustainable production of an array of industrially important products to address bio-economy challenges. Grape winery results in substantial quantities of solid organic and effluent waste, which epitomizes an increasing concentration of pollution problems with direct damage to human health, economy and nature. From the perspective of integrated biorefinery and circular economy, winery waste could be exploited for multiple purpose value-added products before using the biomass for energy security. This review covers state-of-the-art biorefinery opportunities beyond traditional methods as a solution to overcome many current challenges such as waste minimization in grape leaves, stems, seeds, pomace, wine lees, vinasse etc. and the biosynthesis of various high-value bioproducts viz., phenolic compounds, hydroxybenzoic acids, hydroxycinnamic acids, flavonoids, tartaric acids, lignocellulosic substrates etc.. The critical discussion on the valorization of winery waste (solid, liquid, or gaseous) and life cycle assessment was deployed to find a sustainable solution with value added energy products in an integrated biorefinery approach, keeping the environment and circular economy in the background.

Use of barley straw as a support for the production of conidiospores of Trichoderma harzianum

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Barley straw is an excellent support of conidiospores production.

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The addition of mineral salts substantially improves of conidiospores production.

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Pre-treating the barley straw with a water wash favors the conidiation process.

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80 % humidity favors the conidiation of T. harzianum.

In this work was to evaluate the conidiospores production of Trichoderma harzianum using barley straw as substrate. Four growth conditions were used; washed and unwashed barley straw and washed and unwashed barley straw supplemented with mineral salts. The highest spore production was observed when washed barley straw supplemented with mineral salts with 1.56 × 10¹⁰ conidiospores/gram of dry matter (gdm) at 216 h of cultivation was used. The effect of substrate moisture on spore production was studied, three initial moisture levels of the substrate were tested and it was observed that a humidity of 80 % of the substrate improves the production of conidiospores reaching a concentration of 2.35 × 10¹⁰ conidiospores/gdm at 136 h. Finally, conidiospores viability was evaluated for 12 months by keeping them on the conidia and substrate, and viability of 71 % of the conidiospores was observed, so this maintenance method is an excellent means of conserving the conidiospores viability.

Sustainable Organic Dyes from Winemaking Lees for Photoelectrochemical Dye-Sensitized Solar Cells

During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400–600 °C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.

Planning the Flows of Residual Biomass Produced by Wineries for the Preservation of the Rural Landscape

Circular economy aims to create a system that allows an optimal reuse of products and materials. According to an appropriate planning hierarchy, agricultural and agro-food co-products, by-products and wastes should be primarily employed to re-balance soil fertility, and afterwards valorized as new secondary raw materials used in the same agricultural sector or in different industrial chains (e.g., cosmetics, nutraceuticals, etc.). Finally, only at the end of this process, they could be conveyed to energy production through co-generation. In this paper, different residues generated by the wine production chain have been considered with reference to the Basilicata region (Southern Italy). These biomasses have been quantitatively assessed and qualitatively classified, in order to find the most rational and convenient solution for their valorization from a technical, economic and environmental point of view. From the spatial analysis—elaborated by implementing a Geographic Information System—some thematic maps have been obtained, which allow us to highlight the areas with the highest concentration of residues. In this way, focusing the analysis on these areas, some possible strategies for their management and valorization have been proposed, so as to restore soil fertility and contribute to the sustainable preservation of the rural landscape.

Membrane-Based Clarification and Fractionation of Red Wine Lees Aqueous Extracts

Polyvinylidenefluoride (PVDF) hollow fiber membranes prepared in laboratory through the inversion phase method were characterized and used to clarify an aqueous extract from red wine lees. Steady-state permeate fluxes of 53 kg/m²h were obtained in the treatment of the aqueous extract in selected operating conditions. Suspended solids were completely retained by the hollow fiber membranes while bioactive compounds, including polyphenols, anthocyanins, and resveratrol were recovered in the permeate stream. The clarified stream was then fractionated by nanofiltration (NF). Three different commercial membranes, in flat-sheet configuration (NP010 and NP030 from Microdyn-Nadir, MPF36 from Koch Membrane Systems), were selected and tested for their productivity and selectivity towards sugars and bioactive compounds, including phenolic compounds, anthocyanins, and resveratrol. All selected membranes showed high retention towards anthocyanins (higher than 93%). Therefore, they were considered suitable to concentrate anthocyanins from clarified wine lees extracts at low temperature. On the other hand, NF permeate streams resulted enriched in phenolic compounds and resveratrol. Among the selected membranes, the MPF36 exhibited the lowest retention towards resveratrol (10%) and polyphenols (26.3%) and the best separation factor between these compounds and anthocyanins.

Effect of Trichoderma viride biofertilizer on ammonia volatilization from an alkaline soil in Northern China

Ammonia (NH₃) volatilization is one of the primary pathways of nitrogen (N) loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin (pH8.37-8.43) to evaluate the suppression effect of Trichoderma viride (T. viride) biofertilizer on NH₃ volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer (T) decreased NH₃ volatilization by 42.21% compared with conventional fertilizer ((CK), urea), while nonviable T. viride biofertilizer (TS) decreased NH₃ volatilization by 32.42%. NH₃ volatilization was significantly higher in CK and sweet potato starch wastewater (SPSW) treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea (AOA) and ammonium-oxidizing bacteria (AOB). The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH₃ volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.

The effect of lyophilization and storage time on the survival rate and hydrolytic activity of Trichoderma strains

The study evaluates the survivability and storage stability of seven Trichoderma strains belonging to the species: T. harzianum (1), T. atroviride (4), and T. virens (2) after the lyophilization of their solid state cultures on wheat straw. Biomass of Trichoderma strains was freeze-dried with and without the addition of maltodextrin. Furthermore, in order to determine the ability of tested Trichoderma strains to preserve selected technological features, the biosynthesis of extracellular hydrolases (cellulases, xylanases, and polygalacturonases) after a 3-month storage of lyophilizates was investigated. Strains of T. atroviride (except TRS40) and T. harzianum TRS85 showed the highest viability after lyophilization process (up to 100%). After 3 months of storage, T. atroviride TRS14 exhibited the highest stability (95.23%); however, the number of active conidia remained at high level of 10⁶–10⁷ cfu/g for all tested T. atroviride strains and T. harzianum TRS85. Interestingly, after a 3-month storage of lyophilized formulations, most of the tested Trichoderma strains exhibited higher cellulolytic and xylanolytic activities compared to the control, i.e., before freeze-drying process. The highest activities of these enzymes exhibited the following: T. atroviride TRS14–2.37 U/g and T. atroviride TRS25–21.47 U/g, respectively, whereas pectinolytic activity was weak for all tested strains, with the highest value of 0.64 U/g registered for T. virens TRS109.

Whole-Genome Sequence of Starmerella bacillaris PAS13, a Nonconventional Enological Yeast with Antifungal Activity

Starmerella bacillaris is a fermentative yeast commonly found in vineyards. Here, we present the draft genome sequence of S. bacillaris PAS13, a nonconventional enological yeast with a potential role as a biocontrol agent. This gene sequence will provide insights into the genetic basis of yeast activity against gray mold disease (Botrytis cinerea).

Solid state fermentation (SSF): diversity of applications to valorize waste and biomass

Solid state fermentation is currently used in a range of applications including classical applications, such as enzyme or antibiotic production, recently developed products, such as bioactive compounds and organic acids, new trends regarding bioethanol and biodiesel as sources of alternative energy, and biosurfactant molecules with environmental purposes of valorising unexploited biomass. This work summarizes the diversity of applications of solid state fermentation to valorize biomass regarding alternative energy and environmental purposes. The success of applying solid state fermentation to a specific process is affected by the nature of specific microorganisms and substrates. An exhaustive number of microorganisms able to grow in a solid matrix are presented, including fungus such as Aspergillus or Penicillum for antibiotics, Rhizopus for bioactive compounds, Mortierella for biodiesel to bacteria, Bacillus for biosurfactant production, or yeast for bioethanol.

Biocontrol Ability and Action Mechanism of Starmerella bacillaris (Synonym Candida zemplinina) Isolated from Wine Musts against Gray Mold Disease Agent Botrytis cinerea on Grape and Their Effects on Alcoholic Fermentation

Gray mold is one of the most important diseases of grapevine in temperate climates. This plant pathogen affects plant growth and reduces wine quality. The use of yeasts as biocontrol agents to apply in the vineyard have been investigated in recent years as an alternative to agrochemicals. In this work, fermenting musts obtained from overripe grape berries, therefore more susceptible to infection by fungal pathogens such as Botrytis cinerea, were considered for the selection of yeasts carrying antifungal activity. Thirty-six isolates were identified as Starmerella bacillaris, a species recently proven to be of enological interest. Among them 14 different strains were studied and antifungal activity against B. cinerea was demonstrated, for the first time, to be present in S. bacillaris species. The production of volatile organic compounds (VOCs), tested in vitro, was found to be the main responsible of S. bacillaris antifungal effects. All the strains were able to reduce B. cinerea decay on wounded grape berries artificially inoculated with gray mold. The colonization level of wound was very high reaching, after 5 days, a concentration of 10⁶ cells per ml of grape juice obtained after berry crushing. At this cell concentration S. bacillaris strains were used to ferment synthetic and natural musts. The sequential yeast inoculation, performed by adding S. cerevisiae 48 h after S. bacillaris, was needed to complete sugar consumption and determined a significant increase in glicerol content and a reduction of ethanol and acetic acid concentrations. The high wound colonization ability, found in this work, together with the propensity to colonize grape berry and the interesting enological traits possessed by the selected S. bacillaris strains allow the use of this yeast as biocontrol agent on vine and grape berries with possible positive effects on must fermentation, although the presence of S. cerevisiae is needed to complete the fermentation process. This work introduces new possibilities in wine yeast selection programs in order to identify innovative wine yeasts that are simultaneously antifungal agents in vineyards and alternative wine starters for grape must fermentation and open new perspective to a more integrated strategy for increasing wine quality.

Challenges and opportunities of the bio-pesticides production by solid-state fermentation: filamentous fungi as a model

In recent years, production and use of bio-pesticides have increasing and replacing some synthetic chemical pesticides applied to food commodities. In this review, biological control is focused as an alternative, to some synthetic chemical treatments that cause environmental, human health, and food quality risks. In addition, several phytopathogenic microorganisms have developed resistance to some of these synthetic chemicals and become more difficult to control. Worldwide, the bio-pesticides market is growing annually at a rate of 44% in North America, 20% in Europe and Oceania, 10% in Latin and South American countries and 6% in Asia. Use of agro-industrial wastes and solid-state fermentation (SSF) technology offers an alternative to bio-pesticide production with advantages versus conventional submerged fermentations, as reduced cost and energy consumption, low production of residual water and high stability products. In this review, recent data about state of art regarding bio-pesticides production under SSF on agroindustrial wastes will be discussed. SSF can be defined as a microbial process that generally occurs on solid material in the absence of free water. This material has the ability to absorb water with or without soluble nutrients, since the substrate must have water to support the microorganism's growth and metabolism. Changes in water content are analyzed in order to select the conditions for a future process, where water stress can be combined with the best spore production conditions, obtaining in this way an inexpensive biotechnological option for modern agriculture in developing countries.

Production and evaluation of antimycotic and antihepatitis C virus potential of fusant MERV6270 derived from mangrove endophytic fungi using novel substrates of agroindustrial wastes

Among forty endophytic fungal isolates derived from the mangrove plant Avicennia marina, thirty-seven isolates (92.5 %) shown vary antimycotic activity against clinical Trichophyton, Microsporum, and Epidermophyton isolates. The hyperactive wild antagonistic strains Acremonium sp. MERV1 and Chaetomium sp. MERV7 were subjected to intergeneric protoplast fusion technique, and out of 20 fusants obtained, the fusant MERV6270 showed the highest antimycotic activity with the broadest spectrum against all dermatophytes under study. Solid-state fermentation (SSF) showed its superiority for antimycotic/antiviral metabolite production using cost-effective agroindustrial residues. Low-cost novel fermentation medium containing inexpensive substrate mixture of molokhia stalk, lemon peel, pomegranate peel, peanut peel (2:1:1:1) moistened with potato, and meat processing wastewaters (2:1, at moisture content of 60 %) provided a high antimycotic metabolite yield, 33.25 mg/gds, by the fusant MERV6270. The optimal parameters for antimycotic productivity under SSF were incubation period (4 days), incubation temperature (27.5-30 °C), initial pH (6), initial moisture level (60 %), substrate particle size (1.0 mm), and inoculum size (2 × 10(6) spores/gds), which elucidated antimycotic activity to 44.19 mg/gds. Interestingly, wild mangrove Acremonium sp. MERV1 and Chaetomium sp. MERV7 strains and their fusant MERV6270 showed significant inhibition of hepatitis C virus with viral knockdown percent of -82.48, -82.44, and -97.37 %, respectively, compared to the control (100 %), which open a new era in combat epidemic viral diseases.

Mitigating nitrous oxide emissions from tea field soil using bioaugmentation with a Trichoderma viride biofertilizer

Land-use conversion from woodlands to tea fields in subtropical areas of central China leads to increased nitrous oxide (N₂O) emissions, partly due to increased nitrogen fertilizer use. A field investigation of N₂O using a static closed chamber-gas chromatography revealed that the average N₂O fluxes in tea fields with 225 kg N ha⁻¹ yr⁻¹ fertilizer application were 9.4 ± 6.2 times higher than those of woodlands. Accordingly, it is urgent to develop practices for mitigating N₂O emissions from tea fields. By liquid-state fermentation of sweet potato starch wastewater and solid-state fermentation of paddy straw with application of Trichoderma viride, we provided the tea plantation with biofertilizer containing 2.4 t C ha⁻¹ and 58.7 kg N ha⁻¹. Compared to use of synthetic N fertilizer, use of biofertilizer at 225 kg N ha⁻¹ yr⁻¹ significantly reduced N₂O emissions by 33.3%–71.8% and increased the tea yield by 16.2%–62.2%. Therefore, the process of bioconversion/bioaugmentation tested in this study was found to be a cost-effective and feasible approach to reducing N₂O emissions and can be considered the best management practice for tea fields.

Application of Trichoderma harzianum SQR-T037 bio-organic fertiliser significantly controls Fusarium wilt and affects the microbial communities of continuously cropped soil of cucumber

BACKGROUND

The reduction in diversity of the soil microbial community causes the disorder of continuous cropping. The aim of this study was to determine the effects of applying Trichoderma harzianum SQR-T037 bio-organic fertiliser (BIO) on the microbial community in continuously cropped cucumber soil. Four treatments were set: (1) control, where neither seedling nursery soil (N) nor transplanted soil (T) was amended with BIO; (2) N treatment, where nursery soil was amended with BIO (1% w/w) but transplanted soil was not; (3) N + T treatment, where BIO was added to both nursery soil (1% w/w) and transplanted soil (0.5% w/w); (4) uncropped soil, where soil was left uncropped consistently.

RESULTS

A disease index of 72.2% was found for the control treatment, while the N and N + T treatments had disease indices of only 25 and 15% respectively. Analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed that the bacterial communities of the N and N + T treatments were similar to those of the uncropped soil but distinct from those of the control soil. The fungal communities of the N and N + T treatments differed from those of both the uncropped soil and the control.

CONCLUSION

Addition of BIO to both the nursery soil and the transplanted soil can diversify the microbial community in continuously cropped cucumber soil and thus effectively control Fusarium wilt of cucumber plants.

Valorization of winery waste vs. the costs of not recycling

Wine production generates huge amounts of waste. Before the 1990s, the most economical option for waste removal was the payment of a disposal fee usually being of around 3000 Euros. However, in recent years the disposal fee and fines for unauthorized discharges have increased considerably, often reaching 30,000-40,000 Euros, and a prison sentence is sometimes also imposed. Some environmental friendly technologies have been proposed for the valorization of winery waste products. Fermentation of grape marc, trimming vine shoot or vinification lees has been reported to produce lactic acid, biosurfactants, xylitol, ethanol and other compounds. Furthermore, grape marc and seeds are rich in phenolic compounds, which have antioxidants properties, and vinasse contains tartaric acid that can be extracted and commercialized. Companies must therefore invest in new technologies to decrease the impact of agro-industrial residues on the environment and to establish new processes that will provide additional sources of income.

Production of a newly isolated Paenibacillus polymyxa biocontrol agent using monosodium glutamate wastewater and potato wastewater

A phyllosphere bacterial strain EBL-06 was isolated from wheat leaves. The morphology, cultural characteristics, phospholipid fatty acids, physiological and antagonistic fungus activities of this strain were investigated. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relevant bacteria. The results showed that the isolate EBL-06 was a strain of Paenibacillus polymyxa; this strain performed a high level of antagonistic fungus activity toward a broad spectrum of phytopathogens, such as Botrytis cinerea, Cladosporium cucumerinum, Fusarium spp. The isolate EBL-06 can grow well using monosodium glutamate wastewater (MGW) and potato wastewater (PW) as culture medium. The maximum yield of 6.5 x 10(9) CFU/mL of the isolate EBL-06 anti-fungus biocontrol agent was reached in 15 hr cultivation at 28 degrees C, pH 6.0-7.5 using the mixture of MGW and PW (1:9).