Natural Biocides Research Articles

Effectiveness of A Combination of Kitolod Leaves (Laurentia longiflora), Papaya Leaves (Carica papaya), and Lemongrass (Cymbopogon citratus) as Candidates for Biocides on Bactrocera Pests in Citrus sinensis Plants

Bactrocera is a pest that is detrimental to citrus farming. Bactrocera attacks cause developmental disorders in citrus fruit, including changes in fruit color (black spots appear from Bactrocera infection) and premature rot. Bactrocera also has a symbiotic relationship with Liberibacter asiaticus which causes Citrus Vein Phloem Degeneration (CVPD) disease which attacks phloem tissue in citrus plants. Bactrocera pest control was carried out by combining plants that have the potential to be used as biocides, namely kitolod, papaya, and lemongrass plants. This combination was used to switch the habits of fruit farmers who previously used synthetic pesticides to control pests. Natural biocides are expected to have the same effectiveness as synthetic pesticides, but leave no residue on cultivated plants. A combination biocide from the three plants was made using the maceration method to obtain an infusion from each plant. Before being tested on Citrus plantations, an assay was carried out using an olfactometer to determine the effectiveness of the biocides. The research revealed that the combination of these three plants has the potential to be used as a natural biocide without leaving residueand causing damage or other developmental disorders to citrus plants.

Effects of Essential Oils of <i>Vepris heterophylla</i> (Rutaceae) and <i>Xylopia aetiopica</i> (Annonaceae) on Stage II and IV Larvae of <i>Anopheles gambiae</i> Sensu Stricto Giles 1902

Objective: In order to control malaria through the reduction of <i>Plasmodium</i> spp vector populations, a study of the sensibility of <i>A. gambiae</i> ss stage II and IV larvae to <I>V.</I> <i>heterophylla</i> and <i>X. aetiopica</i> essential oils was carried out as well as their combined effect evaluated in the University of Ngaoundere, Adamawa region Cameroon from january to february 2020. Methodology: The tests consisted in evaluating the mortality of <i>A. gambiae</i> ss larvae in the presence of diluted solutions of the essential oils following a WHO (2005) methodology. Results: Bioassays revealed that the essential oils of both plants have remarkable insecticidal properties. At 250ppm, essential oils of <i>V. heterophylla</i> and <i>X. aetiopica</i> induced 100% mortality of stage II larvae after 18h of exposure. In stage IV larvae, the same concentration killed 100% of the larvae after 24h of exposure. The combined effect of the essential oils of the two plants on stage II and IV larvae of <i>A. gambiae</i> ss varied according to the proportion of combination made. In stage II larvae, the combination of <i>V. heterophylla</i> 50% and <i>X. aetiopica</i> 50% essential oils showed better efficacy (LC<sub>50</sub>=42.62ppm; LH<sub>50</sub>=03hr23min27sec), followed by that of <i>V. heterophylla</i> 25% and <i>X. aetiopica</i> 75% (LC<sub>50</sub>=44.24ppm; LH<sub>50</sub>=03hr31min21sec) and that of <i>V. heterophylla</i> 75% and <i>X. aetiopica</i> 25% (LC<sub>50</sub>=53.66ppm; LH<sub>50</sub>=05hr07min59sec). A similar trend was observed in stage IV larvae. Conclusion and application: In sum, due to their proven insecticidal properties against <i>A. gambiae</i> ss, the combination of essential oils of <I>V.</I> <i>heterophylla</i> and <i>X. aetiopica</i> should be highly recommended for the development of natural biocides.

Isolation and identification of fungal biodeteriogens from the wall of a cultural heritage church and potential applicability of antifungal proteins in protection

Fungi are able to permanently damage cultural heritage buildings and stone monuments. Protection against these biodeteriogen fungi is challenging because it may require the use of drastic techniques to remove fungal colonies and chemicals, which can cause further damage, especially on mural paintings. Natural biocides are less damaging, greener, and safer and mainly include essential oils and plant-derived substances. Studies on the applicability of purified antifungal proteins in the conservation of cultural heritage buildings are lacking. In this study, we isolated mold mycoflora from the biodeteriorated inner walls of the Calvinist church of Kézdialbis (Kézdialbis, Romania) and investigated the in vitro antifungal efficacy of Neosartorya (Aspergillus) fischeri antifungal proteins, NFAP and NFAP2 against them. Antifungal susceptibility testing revealed that these proteins inhibited the growth of the most commonly isolated indoor biodeteriogen fungi from the site (Aspergillus creber, Aureobasidium pullulans, Cladosporium sp., Penicillium chrysogenum, and Parengyodontium album) and not common ones (Mucor hiemalis, Sarocladium kiliense) with different spectra and efficacies. A phytopathogen and an entomopathogen species (Pseudopithomyces chartarum and Beauveria pseudobassiana, respectively) were also isolated and described first as fungal biodeteriogens of the inner walls. Among them, P. chartarum was susceptible to NFAP2. Next, we tested the applicability of NFAP and NFAP2 in protecting cultural heritage buildings in a wall model experiment against A. creber. Topical application of both antifungal proteins significantly decreased the area infected by fungi. Scanning electron microscopy of the wall models showed that A. creber had reduced growth and conidiation in the presence of NFAP and NFAP2. This inhibitory activity was maintained for a long time. Strong UV irradiation decreased the protective effect of both proteins in the wall model. Taking into account these results, the high stability of NFAP and NFAP2 in harsh environments, and their bulk recombinant producibility, we suggest that both can be used in the protection and posttreatment of painted walls of cultural heritage buildings to clean up mural painting or to inhibit mold recolonization after mechanical, physical, or chemical decontamination.

SYNERGISM OF ANTIMICROBIAL ACTIVITY OF ANTIBIOTICS WITH BIOCIDES OF NATURAL ORIGIN

Currently, antibiotic therapy remains the primary method for treating infectious diseases in humans. Nevertheless, its effectiveness is rapidly decreasing due to the widespread emergence of resistant pathogens, necessitating the exploration of new treatment options. One potential approach involves the use of antibiotics in combination with other natural compounds. Aim of the review was to summarize the literature data on the synergy of the antimicrobial action of combinations of antibiotics with various biocides against Gram-positive and Gram-negative pathogenic microorganisms. The analysis of literature data has shown that promising compounds for use in combinations with antibiotics include essential oils, other plant components, antimicrobial peptides (both natural and synthetic), and microbial surfactants. In the majority of studies, the researchers calculated the fractional inhibitory concentration index, confirming the synergistic antimicrobial activity of antibiotics and the mentioned compounds. The use of natural biocides in combination with commercial antibiotics, particularly against Gram-negative (including methicillin-resistant) Staphylococcus species and Gram-positive microorganisms (Escherichia coli, Pseudomonas aureginosa, Klebsiella pneumoniae, Proteus mirabilis, Acinetobacter baumannii), enabled to consider these mixtures not only as effective antimicrobial agents but as one of the ways to reduce the effective concentration of antibiotics as well. It should be noted that in the presented studies, the researchers only observed the synergy of antimicrobial activity between a combination of antibiotics and other biocides, without emphasizing the potential mechanisms of interaction between the components of the complex. This likely depended on various factors, including the qualitative composition of natural compounds. Therefore, it was important to continue research not only on the synergy of antimicrobial activity in compound mixtures but also on the underlying mechanisms of their interaction. This would provide insights to enhance their effectiveness in combating resistant microorganisms.

Promising Antifungal Activity of Cedrela fissilis Wood Extractives as Natural Biocides against Xylophagous Fungi for Wood Artwork of Cultural Heritage

Xylophagous fungi are able to thrive inside wood because they produce enzymes that can degrade it and cause significant damage. Due to this process, in the case of wood that forms part of the structure of a building or furniture, xylophagous fungi pose a serious problem that needs to be addressed, as they can compromise the integrity and durability of the wood. The aim of this work was to obtain extractives from Cedrela fissilis wood in order to conduct a preliminary evaluation of their antifungal activity against xylophagous fungi Trametes trogii (white rot), Pycnoporus sanguineus (white rot), and Chaetomium globosum (soft rot). The antifungal activity of the extractives was evaluated against these xylophagous fungi through tests of growth fungal colonies with the extractives in Petri dishes. All the evaluated extractives showed antifungal activity against all the fungi tested, demonstrating their potential use as natural biocides for wood artwork of Cultural Heritage.

In Vitro Viability Tests of New Ecofriendly Nanosystems Incorporating Essential Oils for Long-Lasting Conservation of Stone Artworks.

The study explores the application of natural biocides (oregano essential oil and eugenol, directly applied in solutions or encapsulated within silica nanocapsules) for safeguarding stone cultural heritage from biodeterioration, using green algae (Chlorococcum sp.) and cyanobacteria (Leptolyngbya sp.) as common pioneer biodeteriogens. Core-shell nanocontainers were built for a controlled release of microbicidal agents, a safe application of chemicals and a prolonged efficacy. The qualitative and quantitative evaluations of biocide efficiency at different doses were periodically performed in vitro, after six scheduled intervals of time (until 100 days). The release kinetics of composite biocide-embedding silica nanocapsules were characterized by the UV-Vis spectroscopy technique. Data showed both promising potential and some limitations. The comparative tests of different biocidal systems shed light on their variable efficacy against microorganisms, highlighting how encapsulation influences the release dynamics and the overall effectiveness. Both the essential oils showed a potential efficacy in protective antifouling coatings for stone artifacts. Ensuring compatibility with materials, understanding their differences in biocidal activity and their release rates becomes essential in tailoring gel, microemulsion or coating products for direct on-site application.

Chemical versus Natural Biocide Compounds - Minireview on Antifouling Coatings

Marine biofouling is an old problem, known and studied for centuries, since the beginning of navigation. The accumulation of marine biofouling begins on the submerged portion of an ocean-going vessel or on any installation (equipments, pipes, platforms, etc.) within minutes of contact with seawater. Over time, this accumulation increases the ship's resistance, leading to increases in the physical resistance of the ship in the water, with negative consequences on fuel consumption and greenhouse gas emissions, high maintenance costs (due to corrosion), and a negative impact on the marine environment (due to the release of toic bioactive compounds into the environment and the transfer of invasive species). These environmental issues were identified and recognized by the IMO, which in the early 1990s, through the Marine Environment Protection Committee (MEPC), adopted a resolution recommending that member governments adopt measures to eliminate TBT-based antifouling paints. These recommendations have led to the identification, development, and application of new antifouling technologies that could provide the maritime industry with a significant potential opportunity with an innovative, cost-effective, and efficient approach to the effects of marine biofouling. Our study aimed to make a small incursion in time, through the specialized literature on methods used to combat marine fouling, to highlight new research approaches to the identification and use of natural biocides to replace chemical ones. The targeting of research directions towards the identification of the most environmentally friendly antifouling compounds, in particular natural marine compounds, has been a focus of international researchers in recent years. To achieve this goal, going back to nature is currently the best option, as it could provide us with very effective models for research and development of antifouling coatings. In the development and modeling of new antifouling paints, the influence of the physical-chemical parameters of seawater (pH, salinity, temperature) on the chemical components (active groups) of the biocides used should not be ignored. The aim of this study is to highlight the importance of developing new antifouling paint technologies using biodegradable, non-toic, and environmentally friendly compounds according to international legislation. In recent years there has been an increasing emphasis in research studies on the combination of natural biocides (obtained through the valorization of marine wastes) with natural or synthetic hydrogels whose action is to minimize the attachment of marine fouling.

Actividad insecticida y fitotóxica del aceite esencial de Eryngium foetidum L. colombiano

Eryngium foetidum L. is a biennial herb belonging to the family Apiaceae, which is used extensively as a medicinal plant in most tropical regions. In this research work, the activity of the essential oil (EO) from E. foetidum against the Hyalomma lusitanicum Koch, and its phytotoxicity in germination of seeds of Lolium perenne and Lactuca sativa was studied. E. foetidum EO was isolated by the hydrodistillation technique. Gas chromatography coupled to mass spectrometry (GC-MS) was used to identify the volatile metabolites. Fifteen compounds were found in the E. foetidum EO. The major compounds were E-2-dodecenal (53.0%), trimetilbenzaldehyde (duraldehyde) (14.8%), cyclododecane (4.4%), trans-tetradec-enal (3.9%), decanal (3.6%), and trans-2-dodecen-1-ol (3.0%) and D-limonene (1.5%), respectively. The E. foetidum EO, and two of its individual main compounds (2-dodecenal, and duraldehyde) had low phytotoxic activity when were compared with the percentage of inhibition of germination of the control (carvone), in seeds of L. perenne and L. sativa. The acaricidal activity against Hyalomma lusitanicum was determined using a probit analysis (P>0.05). The essential oil of E. foetidum showed 100% mortality on H. lusitanicum at a concentration of 10 µg µL-1, and LC50 = 4.2 µg µL-1. The results obtained from the essential oil of E. foetidum show a great potential to develop natural biocides for the control of H. lusitanicum due to its chemical composition rich in aldehydes and benzene derivatives, and without adverse phytotoxic effects.

In situ application of alginate hydrogels containing oxidant or natural biocides on Fortunato Depero's mosaic (Rome, Italy)

Stone monuments in outdoor environments are subjected to biodeterioration due to the growth on their surfaces of biofilms responsible of aesthetic, physical and chemical damages. In recent years, the encapsulation of antimicrobial agents into inert matrices has aroused considerable interest thanks to the drastic reduction of the biocide amount needed to counteract the growth of biopatinas. In this study, two biocidal hydrogels containing thyme essential oil (thyme EO) or sodium dichloroisocyanurate (NaDCC), previously tested in the laboratory, were applied on three selected areas of the Depero's mosaic located in the EUR district of Rome (Italy). A simple method to prepare the biocidal hydrogels directly in situ and their easy application on large and vertical surfaces were developed. Before and after the treatment, photographic, colorimetric, and microscopic analyses were performed to highlight the hydrogels' biocidal effectiveness in removing all colonizers. Only one treatment was enough to completely remove the microbial patina constituted of various prokaryotic and eukaryotic microorganisms.This paper is dedicated to the memory of Laura Bruno, who passed away during the peer-reviewed.

Metabolite Formation by Fungal Pathogens of Potatoes (Solanum tuberosum L.) in the Presence of Bioprotective Agents

The potato is a crop of global importance for the food industry. This is why effective protection against pathogens is so important. Fungi as potato pathogens are responsible for plant diseases and a significant reduction in yields, as well as for the formation of mycotoxins. This study focuses on the effect of three natural biocides, yeast Metschnikowia pulcherrima, lactic acid bacteria Lactiplantibacillus plantarum, and aqueous garlic extract, on the improvement of the physiology of planted potato tubers and the reduction in mycotoxin formation. The secondary metabolites produced by the fungal pathogens of genera Fusarium, Alternaria, Colletotrichum, Rhizoctonia, and Phoma in the presence of these biocontrol agents were compared to profiles obtained from contaminated potatoes. Analysis of liquid chromatography coupled with tandem mass spectrometry data showed the presence of 68 secondary metabolites, including the mycotoxins: alternariol, alternariol methyl ether, altertoxin-I, aurofusarin, beauvericin, diacetoxyscirpenol, enniatin B, and sterigmatocystin. The studies showed that the applied biocontrol agents had a positive effect on the physiological parameters of potatoes (including root growth, stem growth, gas exchange, and chlorophyll content index) and on the reduction in the production of mycotoxins and other secondary metabolites by Fusarium, Alternaria, and Phoma.

New frontiers review of some recent conservation techniques of organic and inorganic archaeological artefacts against microbial deterioration.

The information on the advances and technology of some recent conservation methods (2020-2023) of organic and inorganic archaeological objects against microbial deterioration is recorded. An outline of comparative new protective methods for conserving plant-origin organic artefacts {Fibers (manuscripts, textile) and wood}, animal-origin organic artefacts (painting, parchment and mummies) and inorganic stone artefacts were investigated. The work not only contributes to the development of safe revolutionary ways for more efficient safe conservation of items of historical and cultural worth but also serves as a significant diagnostic signature for detecting the sorts of microbial identification and incidents in antiques. Biological technologies (environmentally friendly green biocides) are the most used recent, efficient and safe strategy acceptable as alternatives to stop microbial deterioration and prevent any potential interactions between the biological agent and the artefacts. Also, a synergistic effect of combining natural biocides with mechanical cleaning or chemical treatments was suggested. The recommended exploration techniques should be considered for future applications.

A Bibliometric Analysis of Current Status on Biodeterioration of Cultural Heritage during 2018-2022

Biodeterioration occurs through the availability of biotic and abiotic factors favoring the growth of harmful fungi, bacteria and other microorganisms on cultural heritage. Thus, biodeterioration mechanism has raised a global concern since it is commonly detected on cultural heritage buildings located in specific geographical locations such as southern European countries. This study conducts a bibliometric analysis using VOSviewer and OpenRefine for data cleaning by obtaining data from Scopus database of peer-reviewed publications to provide an overview of scientific literatures on biodeterioration. A total of 537 articles were analyzed within the period of 2018 – 2022 to acquire the current status of biodeterioration issue. 537 documents on biodeterioration were published by 1451 organizations from 68 countries. The co-authorship network map generated the trend of authors in biodeterioration research that identified the most productive author from China and organization from Japan. The co-occurrence network map of the keywords presented the significant interrelations of biodeterioration research field with the development of natural biocides to cope with the colonization of fungi and bacteria on cultural heritage. These results are expected to support the understanding of the intellectual structure of biodeterioration research.

Larvicidal activities of some plants essential oils of the Cameroonian flora against Anopheles gambiae S.L., major vector of malaria in the city of Douala

The present study aims to investigate the larvicidal activity of essential oils of the rhizomes of Zingiber officinalis, the leaves of Tithonia diversifolia and Bidens pilosa on the mature and immature larvae of Anopheles gambiae s.l. The chemical composition of the essential oils was determined by Gas Chromatography (GC) and Gas Chromatography and Mass Spectrometry (GC/MS) coupling. The larvicidal activities of essential oils against An. gambiae s.l. was monitored in the laboratory using the world health organisation protocol. Chemical analysis has shown that all these oils are dominated by monoterpene α-pinene was the major compound found in the essential oils of the leaves of T. diversifolia (69.53%) and B. pilosa (64.43%); while geranial was the majority compound found in the essential oil of Z. officinalis (35.40%). Larvicidal tests showed that the essential oil of the leaves of T. diversifolia was the most effective (LC50 = 70.18 ppm and 92.49 ppm respectively for larvae of immature and mature stages after 24 hours of exposure). From the above, the essential oil of the leaves of T. diversifolia can be recommended for the development of natural biocides against malaria vectors.

Training on Making Biocides Made from Tobacco Leaves in The Dasawisma Group, Mulyorejo Village, Malang City

This community service activity is carried out to help women in the Dasawisma group RT 03 RW 06 Mulyorejo Village Malang City who have difficulty controlling pests during the practice of cultivating vegetables in their home gardens and vacant lands in their neighborhood. This community service program aims to provide skills to the women of the Dasawisma group in making natural pesticides or biocides to control pests that often attack vegetable crops. The approach method used is training in making tobacco-based biocides and mentoring the application of biocides on some cultivated vegetable crops. The stages of implementing the activities include (1) preparation of tools and materials; (2) Training on making biocides; (3) Assistance in the biocide fermentation process; 4) assistance in the application of biocides to vegetable crops. The results of the community service implementation showed that the women in the Dasawisma group were able to make tobacco-based biocides from fermented products. Application technique by spraying all parts of the plant organs with intervals of spraying biocides three times a week, effective in protecting vegetables during the plant maintenance period. This can be seen from the yield of about 80% of the harvested vegetables that are protected from damage due to pest attacks.

Plant essential oils suspended into hydrogel: Development of an easy-to-use protocol for the restoration of stone cultural heritage

The development of phototrophic biofilms deteriorating stone cultural heritage is a well-known phenomenon that causes not only discoloration but also micro-decohesion of substrates. Recently, essential oils (EOs) have resulted as successful natural biocides to be used for the restoration of cultural heritage as an alternative to chemicals. In a first experiment EOs of Lavandula angustifolia Mill. and Thymus vulgaris L. at 5% concentration were tested against cyanobacterial biofilms. Moreover, to develop a suitable protocol for in situ application, diverse concentrations (0.5% - 0.25% - 0.1%) of T. vulgaris EO were encapsulated within an alginate hydrogel and applied for different times on cyanobacterial biofilms. Chemical profiles of the two EOs were investigated via GC-MS, to identify the main plant compounds underlying the biocidal effects. Results showed that T. vulgaris EO, rich in thymol, had the greatest inhibitory effect of photosynthetic efficiency compared to essential oil of L. angustifolia, especially if suspended into hydrogel. The development of such innovative protocol allowed the concentration of the tested essential oil to be 0.1% (v/v), maintaining antimicrobial efficacy against cyanobacteria and reducing the volatility of the terpene components. This innovative method will facilitate the application also on vertical surfaces and the removal of the biofilm.

The application of thymol-loaded chitosan nanoparticles to control the biodeterioration of cultural heritage sites

Biocides are widely used to impede the growth of harmful microorganisms, whose colonization will cause biodeterioration of cultural heritage sites. However, frequent application of biocides is costly and hazardous to both humans and the environment. In this study, a series of thymol-loaded chitosan nanoparticles were prepared by the emulsification-ionic gelation method and verified by instrumental analytical techniques (UV–Vis spectrophotometry, SEM/TEM, FTIR, and TGA/DTG). The results show that thymol is encapsulated within chitosan nanoparticles, thus the release of the natural biocides can be controlled. Compared with free thymol, thymol-loaded chitosan nanoparticles demonstrate a better performance against Aspergillus niger, a class of fungus isolated from the Feilaifeng limestone. This novel strategy could be applied to the preservation and protection of outdoor stone-built cultural heritage sites to reduce the amount and frequency of biocides application.

Secondary metabolites with antibacterial effects from leaves of different hop cultivars during vegetal periods

According to the latest EU regulations it is necessary to cut down the consumption of chemically based pesticides. Several research programmes are focussed on the study of secondary metabolites of plants, which have antimicrobial or antifungal activity against microbial phytopathogens. Other reasons for using of natural biocides are the growth of resistance of phytopathogens against several pesticides; broaden microbial attacks to significant agricultural product for food industry due to the climate changes. The presentation is focussed on the determination of the contents of secondary metabolitesleaves of several cultivars of hop – polyphenols and flavonoids. Methanol crude leaves extracts were tested on biocide effects against selected microbial phytopathogens.

Monitoring the mode of action of synthetic and natural biocides against Aeromonas hydrophila by Raman spectroscopy and chemometrics

We have investigated the mode of action of synthetic biocides, (2-(thiocyanomethylthio) benzothiazole(TCMTB), dichlorophen, (commonly used in leather industry for preservation) and natural biocides, oregano and eucalyptus oils, on Aeromonas hydrophila using Raman spectroscopy in collaboration with multivariate analysis and 2D correlation spectroscopy to evaluate whether Raman spectra acquired contained valuable information to study the action of biocides on bacterial cells. The growth of A. hydrophila in clear and outer edge zone of inhibition differ in their reaction with different biocides, which allows us to highlight the differences as a characteristic of two kinds of bacteria. Such classification helps identify oregano oil as the most effective biocide by altering clear and outer edge zone of bacteria. Standard disk diffusion assay method was used for screening biocide bacteria interactions and later analysed by Raman spectroscopy. The paper also presents the introduction of TCMTB and oregano oil into leather processing stages to examine and determine the antimicrobial effect as an application to real-world setting. Therefore, we conclude that Raman spectroscopy with appropriate computational tools constitutes a powerful approach for screening biocides, which provide solutions to all the industries using biocides including leather industry, considering the potentially harmful effect of biocides to humans and the environment.Graphical abstract

The Efficiency of Biocidal Silica Nanosystems for the Conservation of Stone Monuments: Comparative In Vitro Tests against Epilithic Green Algae

In the last decade, worldwide research has focused on innovative natural biocides and the development of organic and inorganic nanomaterials for long-lasting reliability. In this work, the biocide effects of two different biocides encapsulated in two different silica nanosystems for a multifunctional coating have been performed through in vitro tests, by using Chlorococcum sp. as a common stone biodeteriogen. Zosteric sodium salt (ZS), a green biocide, was compared with the commercial biocide, 2-mercaptobenzothiazole (MBT), widely used in the treatment of cultural heritage. The analyzed systems are the following: silica nanocapsules (NC) and silica nanoparticles (MNP) not loaded with biocides, two nanosystems loaded with ZS and MBT, and free biocides. The qualitative and quantitative evaluations of biocide efficiency were performed periodically, analyzing pigment autofluorescence to discriminate between active and inactive/dead cells. The analyses showed multiple differences. All the nanocontainers presented an initial reduction in chlorophyll’s autofluorescence. For the free biocide, the results highlighted higher efficiency for MBT than ZS. Finally, the nanosystems loaded with the different biocides highlighted a higher activity for nanocontainers loaded with the commercial biocide than the green product, and better efficiency for MNP in comparison with NC.

In Vitro Antibacterial, Antifungal, Nematocidal and Growth Promoting Activities of Trichoderma hamatum FB10 and Its Secondary Metabolites.

Microbial natural biocides have attracted much more attention in recent years in order to avoid the unrestricted use of chemical biocides in the environment. The aim of this study is to analyze the antibacterial and antifungal activities of secondary metabolites and growth promoting, nematicidal, and soil enzyme activity mediated by Trichoderma hamatum FB10. The bactericidal and fungicidal activities were performed using cell-free extract. Results revealed that the selected strain exert antibacterial activity against Acidovorax avenae, Erutimacarafavora, and Xanthomonas campestris. The selected fungal strain FB10 showed antagonistic activity against fungal pathogens such as, S. sclerotiorum, Rhizoctonia solani, Alternaria radicina, Alternaria citri, and Alternaria dauci. Among the bacterial pathogens, A. avenae showed least MIC (30 ± 2.5 µg/mL) and MBC (70 ± 1.25 µg/mL) values. T. hamatum FB10 strain synthesized bioactive volatile secondary metabolite, which effectively inhibited the growth of bacteria and fungi and indicated the presence of 6-pentyl-alpha-pyrone as the major compound (67.05%). The secondary metabolite synthesized by T. hamatum FB10 showed nematicidal activity against M. incognita eggs. Egg hatch inhibition was 78 ± 2.6% and juvenile stage mortality rate was 89 ± 2.5% when the strain FB10 was treated with nematode. The cell free extract of T. hamatum FB10 showed protease, amylase, cellulase, chitinase, glucanase activities. T. hamatum FB10 inoculated with green gram increased 11% plant height, compared to the control. The fresh weight of the experimental group inoculated with T. hamatum FB10 increased 33.6% more compared to the control group. The green gram seedlings inoculated with T. hamatum FB10 increased 18% more dry weight than control group. Soil enzymes such as, urease, phosphatase, catalase and saccharase were improved in the soil inoculated with T. hamatum FB10. These biochemical components play potent role in soil fertility, energy conversion, and in soil organic matter conversion.