Trichoderma citrinoviride: Anti-Fungal Biosurfactants Production Characteristics

The mechanism of direct impact of Trichoderma fungi on other organisms is a multilayer process. The level of limiting the growth of other microorganisms is determined by the strain and often by the environment. Confirmation of the presence of extracellular biosurfactants in certain strains of Trichoderma considered as biocontrol agents was regarded as a crucial topic complementing the characterization of their interactive mechanisms. Selected strains of T. citrinoviride were cultured in media stimulating biosurfactant biosynthesis, optionally supplemented with lytic enzyme inducers. Results confirmed the anti-fungal properties of surface-active compounds in the tested culture fluids. Preparations that displayed high fungal growth inhibition presented marginal enzymatic activities of both chitinases and laminarinases, implying the inhibitory role of biosurfactants. Fractions from the foam of the culture fluid of the C1 strain, cultured on Saunders medium, and HL strain on MGP medium, without an additional carbon source, exhibited the most prominent ability to inhibit the growth of phytopathogens. Filamentous fungi capable of producing fungicidal compounds, including surfactants, may find applications in protecting the plants against agri-food pathogenic molds.

The Effect of Trichoderma citrinoviride Treatment under Salinity Combined to Rhizoctonia solani Infection in Strawberry (Fragaria x ananassa Duch.)

Trihoderma citrinoviride protects plants from diseases by functioning as antagonists of many pathogenic fungi or by triggering the antioxidant defense system in plants. In the present study, to uncover the possible alleviative role of Trichoderma against salinity and Rhizoctonia solani infection, strawberry plants were pretreated Trichoderma citrinoviride and then subjected to salinity, R. solani and combined salinity and R. solani. The effect of T. citrinoviride on the alleviation of the effects of salt stress and Rhizoctonia solani infection was investigated by analysing leaf dry weight, PSII efficiency, and the activity of some antioxidant enzymes in the leaves of strawberry plants. T. citrinoviride improved competitive capability against salinity and R. solani infection. It showed 79% inhibition of the growth of pathogen R. solani. T. citrinoviride reduced 63% of the severity of disease in the leaves. Trichoderma pretreatment maximized plant dry weight. The T. citrinoviride-pretreated plants showed higher levels of PSII efficiency (Fv/Fm). Decreased lipid peroxidation and H2O2 accumulation compared to untreated seedlings under salt stress and R. solani infection was observed. Trichoderma-pretreated and –untreated plants respond differently to salt stress and R. solani infection by means of antioxidant defense. As compared to untreated seedlings, treated seedlings showed significantly lower activities of antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POX), cell wall peroxidase (CWPOX) under salt stress and R. solani infection, indicating that treated seedlings might sense lower stress as compared to untreated seedlings. The study reports the effective adaptive strategy and potential of T. citrinoviride in alleviating the negative impact of salt stress and R. solani infection in strawberry.

Evaluation of Activity of Tannases Produced by Isolated from Syrian Woody Soils Trichoderma citrinoviride and T. brevicompactum on Tannins Degradation

This study was conducted during the period 2019–2020 to identify Trichoderma spp. isolated from woody soils and assessing their efficacy for biodegradation of tannins through tannase enzyme activity produced. Results obtained confirmed the presence of two species; Trichoderma citrinoviride, which was isolated from Maysalon area near Damascus, and characterized by yellowish green colony with dense growth of spores at the center of the colony, and Trichoderma brevicompactum isolated from the Balluran area near Lattakia characterized by yellow colonies with concentric rings. Trichoderma citrinoviride had higher biodegradation activity, measured by degrading different tannins concentrations (2, 4, 6%) collected from Queircus coccifera from Bmelka area in Tartous in liquid medium and led to 85, 87 and 90% degradation, for the three concentrations, respectively, following 12 days incubation. The activity of the produced tannase was measured to be 37.9 units/mg. Whereas, the decomposition rate of the three tannin concentrations by Trichoderma brevicompactum reached 67, 80 , 89%, respectively, again after 12 days of incubation, with enzyme activity measured to be 35.2 units/mg. Keywords: Trichoderma, tannins, tannase, biodegradation, enzyme activit

Combined Use of Two Trichoderma Strains to Promote Growth of Pakchoi (Brassica chinensis L.)

Trichoderma spp., which widely exist in nature, are always used as plant growth-promoting stimulants. However, there is little reporting about the combined use of Trichoderma strains to promote growth of plants. We explored two different Trichoderma strains (Trichoderma atroviride LX-7 and Trichoderma citrinoviride HT-1) and a mixture of the two on the growth-promoting effects of pakchoi. In this study, in vitro-promoting traits of two Trichoderma strains were determined, and six treatments were used: T. atroviride LX-7, T. citrinoviride HT-1, different mixtures of these two (1:1, 1:2 and 2:1) and no inoculation in the seed germination and pot experiment. The results showed that T.atroviride LX-7 and T. citrinoviride HT-1 had the ability of siderophore and indol acetic acid (IAA) production, and LX-7 had the capacity for potassium solubilization. The highest seed germination percentage (GP), germination energy (GE), germination index (GI), vitality index (VI) and growth of radicles and plumules was observed in the LX-7 + HT-1 (1:1) combination, the highest biomass and quality of plants was observed in the LX-7 + HT-1 (1:2) inoculation (followed by a single LX-7 or HT-1 strain inoculation), while the lowest values were obtained in the untreated seeds or plants. On the basis of this study, combined use of two Trichoderma strains had greater benefits for growth and quality of pakchoi, making this formulation attractive for future field applications.

Study on Trichoderma Citrinoviride 31/4 – Antagonistic Activity and Jasmonic Acid

The genus Trichoderma was first identified by the German scientist Persoon in 1974, and there are currently 89 species in the genus. Trichoderma fungi often break down organic compounds in the soil into minerals and plays an important role in soil fertility formation. Trichoderma citrinoviride 31/4 isolated from the soil forms a colony with light yellow-green mycelium on the surface of the PDA medium, with spherical spore, septate hyphae, branched conidophores. Trichoderma citrinoviride 31/4 had antagonistic activity of 66.7% against Cladosporium fulvum, 77.5% against Alternaria alternata, and 59.1% against Fusarium oxysporium after 7 days. Experimental results showed that the progress of tomato alternariosis treated with Trichoderma citrinoviride 31/4 was neutralized from the 7th day, and the biological activity was averagely 74% on the 21st day. Trichoderma citrinoviride 31/4 contains 0.0135 mg / kg of jasmonic acid in plants treated with 109 cell / ml and 0.0076 mg/kg in plants treated with 108 cell / ml.

Bioconversion of Sweet Sorghum Residues by Trichoderma citrinoviride C1 Enzymes Cocktail for Effective Bioethanol Production

Improved cost-effective bioethanol production using inexpensive enzymes preparation was investigated. Three types of waste lignocellulosic materials were converted—for the production of enzyme preparation, a mixture of sugar beet pulp and wheat bran, while the source of sugars in hydrolysates was sweet sorghum biomass. A novel enzyme cocktail of Trichoderma citrinoviride C1 is presented. The one-step ultrafiltration process of crude enzyme extract resulted in a threefold increase of cellulolytic and xylanolytic activities. The effectiveness of enzyme preparation, compared to Cellic® CTec2, was tested in an optimized enzymatic hydrolysis process. Depending on the test conditions, hydrolysates with different glucose concentrations were obtained—from 6.3 g L−1 to 14.6 g L−1 (representing from 90% to 79% of the CTec2 enzyme yield, respectively). Furthermore, ethanol production by Saccharomyces cerevisiae SIHA Active Yeast 6 strain DF 639 in optimal conditions reached about 120 mL kg d.m.−1 (75% compared with the CTec2 process). The achieved yields suggested that the produced enzyme cocktail C1 could be potentially used to reduce the cost of bioethanol production from sweet sorghum biomass.

Isolation and effect of Trichoderma citrinoviride Snef1910 for the biological control of root-knot nematode, Meloidogyne incognita

Background Root-knot nematode is one of the most significant diseases of vegetable crops in the world. Biological control with microbial antagonists has been emerged as a promising and eco-friendly treatment to control pathogens. The aim of this study was to screen and identify novel biocontrol agents against root-knot nematode, Meloidogyne incognita. Results A total of 890 fungal isolates were obtained from rhizosphere soil of different crops and screened by nematicidal activity assays. Snef1910 strain showed high virulence against second stage juveniles (J2s) of M. incognita and identified as Trichoderma citrinoviride by morphology analysis and biomolecular assay. Furthermore, T. citrinoviride Snef1910 significantly inhibited egg hatching with the hatching inhibition percentages of 90.27, 77.50, and 67.06% at 48, 72, and 96 h after the treatment, respectively. The results of pot experiment showed that the metabolites of T. citrinoviride Snef1910 significantly decreased the number of root galls, J2s, and nematode egg masses and J2s population density in soil and significantly promoted the growth of tomato plants. In the field experiment, the biocontrol application showed that the control efficacy of T. citrinoviride Snef1910 against root-knot nematode was more than 50%. Meanwhile, T. citrinoviride Snef1910 increased the tomato plant biomass. Conclusions T. citrinoviride strain Snef1910 could be used as a potential biological control agent against root-knot nematode, M. incognita.

Evaluation ofTrichoderma atroviride and Trichoderma citrinoviride growth profiles and their potentials as biocontrol agent and biofertilizer

BackgroundTwo Trichoderma species (T. atroviride and T. citrinoviride) were evaluated for their potential to have Trichoderma-based biological control agent and biofertilizer properties.Materials and MethodsEight Trichoderma spp. were identified by molecular methods. The mycoparasitic activities against different phytopathogenic fungi and their capacity to produce extracellular lytic enzymes were investigated. Furthermore, indole-3-acetic acid production and phosphate solubilization capabilities of Trichoderma spp. were evaluated together with the effect of some physical parameters and different carbon:nitrogen sources on mycelial growth and conidium production.Results and DiscussionAll strains exhibited lytic enzymes and indole-3 acetic acid production as well as phosphate solubility characteristics. Trichoderma citrinoviride demostrated more mycoparasitic activity against Fusarium oxysporium than T. atroviride whereas T. atroviride was found more effective against Rhizoctonia solani. In particular, at lower temperatures, conidium production of T. atroviride strains were significantly higher than T. citrinoviride strains. Both strains grew well on all carbon sources tested. The effect of organic nitrogen sources on growth were notably higher than inorganic nitrogen sources.ConclusionThe results provided valuable insight in both the highest mycelial growth and conidia production conditions of these cultures for further similar studies related to development of Trichoderma-based new commercial biological control and biofertilizer formulations in different agro-climatic regions.