Assessing the potential of a Trichoderma-based compost activator to hasten the decomposition of incorporated rice straw

The potential for a Trichoderma-based compost activator was tested for in-situ rice straw decomposition, under both laboratory and field conditions. Inoculation of Trichoderma caused a 50% reduction in the indigenous fungal population after 2 weeks of incubation for both laboratory and field experiments. However, the Trichoderma population declined during the latter part of the incubation. Despite the significant reduction in fungal population during the first 2 weeks of incubation, inoculated samples were found to have higher indigenous and total fungal population at the end of the experiments with as much as a 300% increase in the laboratory experiment and 50% during day-21 and day-28 samplings in the field experiment. The laboratory incubation experiment revealed that inoculated samples released an average of 16% higher amounts of CO2 compared to uninoculated straw in sterile soil samples. Unsterile soil inoculated with Trichoderma released the highest amount of CO2 in the laboratory experiment. In the field experiment, improved decomposition was observed in samples inoculated with Trichoderma and placed below ground (WTBG). From the initial value of around 35%, the C content in WTBG was down to 28.63% after 42 days of incubation and was the lowest among treatments. This is significantly lower compared with NTBG (No Trichoderma placed below ground, 31.1% C), WTSS (With Trichoderma placed on soil surface, 33.83% C), and NTSS (No Trichoderma placed on soil surface, 34.30% carbon). The WTBG treatment also had the highest N content of 1.1%. The C:N ratio of WTBG was only 26.27, 39.51% lower than the C:N ratio of NTBG, which is 43.43. These results prove that the Trichoderma-based inoculant has the potential to hasten the decomposition of incorporated rice straw.

Metagenomic analysis decodes the fungal diversity of bio-dynamic preparations

Aim: Biodynamic farming system involves use of 8 different biodynamic preparations (BD 500-BD 507). Multi functionality of any ecosystem is due to its microbial diversity and community composition of microbes. So the present study was aimed to determine the total fungal population viz. unculturable ones, metagenomic analysis was done. Methodology: In the present study, 18S rDNA sequencing of V3-V4 amplicon regions was performed to identify and characterize fungal diversity, which existed in these preparations. Results: Alpha diversity was found to be maximum in BD506 with 868 OTU (operational taxanomic units) and minimum in BD507 with 254 OTU. At phylum level, the most abundant phylum was Ascomycota as recorded in 7 BD preparations with exception in the BD 500 (Unassigned). At genus level highest percentage of OTU abundance was observed for unassigned genus in all BD preparations, except Mortierella in BD 500 and BD 502; Microascus in BD 501 and BD504; Gymnoascus in BD503, Scedosporium in BD 505, Mucor in BD 506 and Hyphopichia in BD 507. On the basis of species diversity, BD502, 503 and 506 showed high percentage of OTU abundance for Mucor racemosus, while Mortierella oligospora was abundant in BD500, Dipodascus geotrichum in BD 501, Kernia pachypleura in BD504, Petriella setifera in BD505 and Hyphopichia burtonii in BD 507. Interpretation: This indicated a unqiue class of fungus predominating each type of BD preparation. Furthermore, a large proportion of unassigned fungi at phylum and genus level were detected in metagenome analysis which might have specific roles in contributing for their overall effectiveness of each kind of BD preparations.

Screening of halotolerant microfungi isolated from hypersaline soils of Algerian Sahara for production of hydrolytic enzymes

The Algerian Sahara contains numerous hypersaline ecosystems including salt lakes in which the fungal diversity has not been characterized. The abundance and diversity of soil microofungi in three salt lakes in southeastern Algeria was investigated together with their profiles of hydrolytic enzyme. Fungal population size and relative abundance were determined in about 75 soil samples by plate count. From 69 fungal isolates, 46.38% were Aspergillus, 20.29% were Penicillium and 11.59% belonging to Cladosporium genus. The sixty-nine isolates have been studied at different constant temperatures and salinities. All fungal isolates are halotolerant or halophiles with the ability to grow at 50°C. The screening for extracellular halophilic enzymes at 40°C showed that 69.57% of the isolates were able to produce at least two types of the screened enzymes. Protease was the most abundant enzyme detected in 60.87% of the total isolates. The results obtained of all the growth tests indicate the adaptability of fungal isolates tested to the extreme conditions and their possible utilisation as producers of halophilic-active hydrolytic enzymes.

Fungal Population and Physicochemical Characteristics of Abattoir-Impacted Soil in Iwofe, Rivers State

Aim: To determine the fungal population and physicochemistry of abattoir impacted soil in Iwofe, Rivers State. Study Design: This study focused on Abattoir impacted soil. Statistical analysis of data and interpretation was carried out. Place and Duration of Study: Abattoir impacted soil was collected from three points in an abattoir located in Iwofe, Rivers State while the unpolluted soil which served as control was collected from the Rivers State University, Port Harcourt in January, 2021. Methodology: Standard microbiological techniques were used: the fungal population was determined by inoculating aliquots of an appropriate dilution resulting from a ten-fold serial dilution on prepared Sabouraud dextrose agar plates in duplicates. Plates were later incubated for 3-5 days after which colonies were enumerated and used in obtaining the fungal population in the soil samples while distinct colonies were subcultured for macroscopic and microscopic identification of fungi. The physicochemical parameters and heavy metals were analyzed using standard methods. Results: Fungal load in the control and abattoir impacted soil were 1.09×105 and 3.9×104 CFU/g, respectively. The fungal load of the control soil was significantly higher (P˂0.05) than the abattoir impacted soil. The fungal isolates identified in the abattoir impacted soil were Microsporium sp, Aspergillus niger and Candida sp while Aspergillus niger, Aspergillus flavus, Fusarium sp, Penicillium sp, Mucor sp and Rhizopus sp were identified from the control soil. The pH, temperature, nitrate and phosphate of the abattoir soil were 6.7, 28.33℃, 27.83(mgKg-1) and 1055(mgKg-1), respectively. The concentrations of Cadmium, Iron and Lead in the abattoir Impacted soil and control soil were 0.81, 563.35 and 7.12 mgKg-1, 0.51, 582.0 and 3.18 mgKg-1, respectively. The physico chemistry and heavy metals in the abattoir soil were within acceptable limits. Discussion and Conclusion: The findings from this study showed that heavy metals in abattoir impacted soil had an impact in the fungal population which led to the isolation of only three fungal isolates belonging to Microsporium sp, Candida sp and Aspergillus niger. More so, despite the presence of heavy metals in the abattoir impacted soil, the metals were all within permissible limits. Thus, the abattoir impacted soil was not heavily polluted.

Assessment of postharvest soil fungal population with special reference to Trichoderma in eggplants

The research work was done to assess the postharvest soil fungal population and to find out the relation between population dynamics of Trichoderma and soil borne disease of 41 eggplant cultivars. Soil samples collected from IPM lab germplasm maintenance field at post-harvest stage were analyzed for microbes in dilution plate technique. Fungal colonies appeared in each plate were counted and made their average. Incidence and severity of Fusarium wilt and Sclerotium collar rot in the plot of 41 eggplant varieties were recorded at flowering-fruiting stage. The highest total soil fungal population was estimated from the plot soil of eggplant var. Singnath S (IPM- 42) that was 40.75×104. The var. Bijoy had the lowest fungal population that was 7.5×104. A comparison between Trichoderma population and other fungal population was made. Different eggplant cultivars had variation in the population of two important soil fungi- Trichoderma and Fusarium. The total populations of Trichoderma and Fusarium in the plot soil of 41 eggplant varieties were 129.75 and 348.75 × 104 per gram of soil, respectively. The average number of colonies of Trichoderma varied with the range (1-8.25) per plate. Fusarium varied with the range from (2-22.50). In 20 important eggplant varieties out of 41, both Fusarium wilt and Sclerotium collar rot incidence ranged between 0.00 to 40.00%. The variety Puta begun had the highest incidence of Fusarium wilt with the highest soil population of Fusarium oxysporum against the absence of Trichoderma harzianum. The disease incidence at flowering-fruiting stage was negatively correlated with the population of Trichoderma. Disease severity decreased with the increase in Trichoderma population. Increase of Trichoderma population, decreased the population of other fungi (Fusarium oxysporum and Sclerotium rolfsii). These results are clearly indicating that Trichoderma might have the antagonistic potential and might contribute to the reduction of incidence of soil-borne diseases. Progressive Agriculture 32 (1): 31-42, 2021

Long Term Influence of Manure- Fertilizer Treatments on Soil Biological Health and Yield of Rice Crop

Long term manure fertilizer experiments provide valuable information on the impact of long term adoption of nutrient management systems with varying sources, types and combinations of plant nutrient inputs on soil fertility and productivity. A Permanent Manurial Experiment (PME) under rice monoculture is in operation since 1975 at the central farm of the Agricultural College and Research Institute, Madurai. The present study was taken up to evaluate the effects of different manure – fertilizer schedules on certain properties of the soil, available nutrient status, total microbial population and enzyme activities of the soil. In this experiment, four main plot treatments involving three organic manures viz., FYM, GLM and UC @ 12.5 t ha-1 with a no manure control and eight sub plot treatments viz., control N,P,K,NP,NK,PK and NPK. The 57th rice crop (Var ADT 49) was raised during rabi 2016 with NPK recommended dose of 150:50:50 kg N, P2O5 and K2O respectively. The maximum total bacterial population (128 x 106 CFUg-1 of dry soil), total fungal population (70 x 104 CFUg-1 of dry soil) and total actinomycetes population ( 84 x 103 CFUg-1 of dry soil) were registered in the plots that received integrated application of GLM @ 12.5 tha-1 and 100% recommended NPK (150:50:50 kgha-1 during this season). However compared to the bacterial population, the inorganic fertilizers did not have much influence on the fungal population as that of the organic manures. Integrated application of GLM @ 12.5 tha-1 along with N fertilizer with or without P and K registered the maximum dehydrogenase activity, during tillering stage of rice crop. The maximum yields of rice grain and straw (4790 and 8701 kg ha-1) respectively was recorded in the treatments that received GLM and NPK and it was evident that the inclusion of FYM or GLM or Urban compost along with NPK, N, NP, and NK fertilizers recorded significantly higher yields than their individual applications and unmanured and unfertilized control.

The diversity of fungal population from grape harvest to young wine in Small Carpathian wine region

The study aimed to identify the filamentous fungi and yeast mycobiota found on the surface and in grapes, grape must, and wine obtained from four red grape varieties: Alibernet, Dornfelder, Blue Frankish, Cabernet Sauvignon, and four white grape varieties: Green Veltliner, Rheinriesling, Pinot Blanc, Sauvignon. Grapes from vineyard Vrbové located in southwestern Slovakia were used for the research in 2020. The identification of filamentous fungi was performed using the macroscopic and microscopic observations and yeasts were identified by MALDI-TOF Mass Spectrometer. A total of 642 isolates were obtained. Grapes were rich in diversity of filamentous fungi (13 genera) and must on yeasts (8 genera). Penicillium, Botrytis, and Hanseniaspora uvarum were identified in both grapes and must. Three of the fungal genera identified by conventional or molecular techniques from the surface of red grape varieties were predominant: Alternaria (26%), Botrytis (21%), and Issatchenkia terricola (13%), two from endogenous mycobiota: Hanseniaspora uvarum (45%) and Botrytis (17%), four from the surface of white grape varieties: Penicillium (25%), Botrytis (21%), Alternaria (16%) and Hanseniaspora uvarum (15%), and three from endogenous mycobiota: Botrytis (44%), Hanseniaspora uvarum (23%) and Alternaria (20%). Saccharomyces cerevisiae, Candida krusei, C. utilis, and Cryptococcus neoformans were identified only in wine.

DIVERSITY AND DISTRIBUTION OF SOIL FUNGI ISOLATED FROM THE CABBAGE (BRASSICA OLERACEA VAR. CAPITATA) RHIZOSPHERE

We have been working on the traditional way to discourse microscopic fungal population present in the rhizospheric soil of Cabbage (Brassica oleracea var. capitata). These fungi are crucial for the decomposition of organic carbon, cycling of nitrogen and phosphorus, and belowground carbon sequestration. Their role as parasite, saprophyte, mutualism and commensalism is also well established. The objective of this study was to analyze soil and determine the fungus genera from the rhizospheric soil of Cabbage from the area of Armpora, Binner, Chakloo, Janbazpora, Ladoora, Muslimabad, Nadihal and Punchatra villages which come under, Dist. Baramulla, Jammu and Kashmir. The Cabbage plant rhizospheric soil was obtained from various research locations marked from the said villages. Research method applied was a survey with the intent of soil sampling. The soil samples were taken from 1-10 cm deep soil for sampling purpose. The result recorded from soil samples were then analyzed descriptively and described based on their macro and micro morphology. Then, the collected fungus was identified by using identification manual for fungus. Fungi such as Aspergillus, Alternaria, Chaetomium, Cladosporium, Curvularia, Fusarium, Mortirella, Mucor, Nigrospora, Penicillium, Rhizoctonia, Phoma, Trichoderma, Verticillium and Sterilia mycelia were most frequently recorded.

DNA metabarcoding of forensic mycological samples

Background DNA metabarcoding and massive parallel sequencing are valuable molecular tools for the characterization of environmental samples. In forensic sciences, the analysis of the sample’s fungal population can be highly informative for the estimation of post-mortem interval, the ascertainment of deposition time, the identification of the cause of death, or the location of buried corpses. Unfortunately, metabarcoding data analysis often requires strong bioinformatic capabilities that are not widely available in forensic laboratories. Results The present paper describes the adoption of a user-friendly cloud-based application for the identification of fungi in typical forensic samples. The samples have also been analyzed through the QIIME pipeline, obtaining a relevant data concordance on top genus classification results (88%). Conclusions The availability of a user-friendly application that can be run without command line activities will increase the popularity of metabarcoding fungal analysis in forensic samples.

Fungi carried over in jute bags – a smoking gun for aflatoxin contamination in the food supply chain

India is the largest jute and fifth largest maize producing country in the world. In India maize is commonly stored and transported in jute bags which are used multiple times. Aflatoxin contamination of maize is a major issue in India. This study evaluated the potential impact of re-using jute bags on the risk of aflatoxin contamination of maize in the food supply chain. A total of 121 jute bags were collected in India; 95 had been used for maize and 26 bags were new. Significantly higher numbers of viable aflatoxigenic fungi were counted from re-used bags (27.8 times) (P<0.05), than the number from new bags. There was no significant difference between aflatoxin concentration found in the re-used jute bags and the new jute bags (P>0.05). Further analysis revealed that the aflatoxigenic fungal population (3.0 times) and aflatoxin concentration (1.2 times) were significantly higher in jute bags that had been used for maize with higher aflatoxin contamination (14-188.4 μg/kg total aflatoxins) than in those that had been used for maize with lower contamination (0.8-5.4 μg/kg total aflatoxins) (P<0.05). The significant positive correlation (P<0.05) between the aflatoxigenic fungal population of used jute bags and aflatoxin contamination of their packed maize indicated there is a risk of cross-contamination in the supply chain introduced by re-using jute bags. This is the first study to systematically reveal the potential impact of re-using jute bags on the fungal population and aflatoxin contamination risk. The application of readily applied treatments to re-used jute bags would help to minimise the aflatoxin contamination.