XYLANASE ACTIVITY OF ASPERGILLUS NIGER AT DIFFERENT ECOLOGICAL CONDITIONS

Maximization of xylanase activity at different media, temperature, pH and salt concentration has been presented in this paper. YpSs, Czapek dox and Malt extract medium were taken for evaluation of optimum growth and activity. Amongst all tested media, YpSs showed the highest growth. Three different natural carbon substitute i.e., wheat husk, rice husk and sugarcane baggase were used for xylanase activity. Maximum enzyme activity was observed in test fungus at rice husk. Production and maximum xylanase activity at rice husk has been observed at different temperatures, pH and Salt concentrations. The highest xylanase activity has been observed on day 5 at temperature 32° C, pH 6.5 and salt concentration of 2%.

FOUR SOLVENT EXTRACTION OF CINNAMOMUM CAMPHORA XYLEM AND ANALYSIS OF THE ANTI-FUNGAL ACTIVITY OF THE EXTRACTIVES

Four solvents including distilled water, acetone, ethyl acetate and petroleum ether were used to extract xylem of C. camphora. The differences in chemical compounds of xylem of C. camphorawere analyzed by gas chromatography/mass spectrometry(GC/MS)and the anti-fungal activityof C. camphoraextractives on Coriolus versicolor(CV), Trametes versicolor(TV),Poria vaporaria (PP) and Gloeophyllum trabeum(GT) were tested. The result showed that the chemical composition and relative content of the four different solvent extracts were different.A large number of chemical compounds in the C. camphoraextractives had a variety of biological activity and certain application value. The growth inhibitory rates of ethyl acetate extracts of C. camphora on PP, CV, TV and GTwere 52.24%, 52.51%, 43.26%, and 54.63%, respectively. According to the concentration for 50% of maximal effect, the inhibitory order on test fungus were GT > PP > CV > TV.

Impact of different sterilization techniques and mass loss measurements on the durability of wood against wood-destroying fungi

The biological durability of wood is frequently determined in laboratory tests with monocultures of different decay fungi under ideal conditions for fungal growth. To avoid contamination with mould and inhibition of fungal growth, wood specimens need to be sterilized using different methods. To determine the mass loss of wood blocks during incubation, the initial total dry mass is needed but should be determined without oven-drying to avoid the loss of volatile compounds of the tested wood. In this study the effect of different sterilization techniques in combination with different methods of determining the oven-dry weight on mass loss (MLF) in agar plate wood block tests was investigated. No significant MLF differences were observed between sterilization through gamma radiation, steam, autoclaving, ethanol dipping and oven-drying. Solely, non-sterilized specimens showed reduced MLF, since the test fungus was inhibited by mould growth. Oven-drying of wood species that contain volatile and resistance-affecting compounds such as Scots pine (Pinus sylvestris) led to reduced biological durability and should either be avoided or adapted to kiln-drying temperatures usually applied in practice.

Cyclohumulanoid Sesquiterpenes from the Culture Broth of the Basidiomycetous Fungus Daedaleopsis tricolor

A series of cyclohumulanoids, i.e., tricocerapicanols A–C (1a–1c), tricoprotoilludenes A (2a) and B (3), tricosterpurol (4), and tricoilludins A–C (5–7) were isolated along with known violascensol (2b) and omphadiol (8) from the culture broth of Daedaleopsis tricolor, an inedible but not toxic mushroom. The structures were fully elucidated on the basis of NMR spectroscopic analysis, and the suggested relative structures were confirmed via density functional theory (DFT)-based chemical shift calculations involving a DP4 probability analysis. In the present study, the 1H chemical shifts were more informative than the 13C chemical shifts to distinguish the diastereomers at C-11. The absolute configurations of 1–5 were determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectra. For 6 and 7, the same chirality was assigned according to their biosynthetic similarities with the other compounds. The successful assignment of some Cotton effects was achieved by utilizing DFT calculations using simple model compounds. The plausible biosynthesis of 1–7 was also discussed on the basis of the structural commonality and general cyclohumulanoid biosynthesis. Compounds 2a and 5 were found to simultaneously induce hyphal swelling and branching at 5.0 μg/mL against a test fungus Cochliobolus miyabeanus.

IN-VITRO BIOCONTROL POTENTIAL AND MECHANISM OF INHIBITION OF INDIGENOUS TRICHODERMA ISOLATES FROM SOUTHEAST SULAWESI PROVINCE OF INDONESIA AGAINST SCLEROTIUM ROLFSII

Sclerotium rolfsii is an important plant pathogen and causes disease in some cultivated plants especially in Southeast Sulawesi. S. rolfsii is mainly controlled by using synthetic fungicides which are hazardous to human, livestock and environment. In the present study, eleven species of Trichoderma, indigenous to Southeast Sulawesi, were tested for their in vitro efficacy against S. rolfsii to replace deleterious fungicides. The analysis of variance showed significant results of the indigenous Trichoderma spp. against S. rolfsii. in in vitro test. All the Trichoderma isolates inhibited the growth of the test fungus differently. After three days of inoculation, ST1 treatment showed the highest inhibitory ability by 55.56% but was not significantly different from the inhibitory abilities of ST2, ST3, ST5, ST6, ST7, ST9, ST10, and ST11 treatments. The treatment ST4 and ST8 gave inhibitory abilities by 25.22% and 26.11% respectively. Furthermore, the data after 4, 5, 6 and 7 days after inoculation were also significant. The ST1 (DKT isolate) treatment gave the maximum inhibition of the test fungus after all the time intervals of seven days. On the other hand, ST8 (LKP isolate) treatment gave the lowest inhibitory ability. DKT isolate of indigenous Trichoderma had the highest inhibitory ability reaching to 55.56% on third days of observation while LKP isolate had the lowest inhibitory ability of 16.67% and then decreased subsequently. the antagonistic mechanisms of Trichoderma isolates were space and nutrition competition, antibiosis, and mycoparasitism. These results showed that Trichoderma indigenous to Southeast Sulawesi had better in vitro inhibitory ability to control S. rolfsii by the above-mentioned mechanisms.

Fungicidal properties of the medium from SCOBY microorganism cultivation in saturated wood against Coniophora puteana fungus

Effects were assessed for the post-culture liquid medium originating from the cultivation of microorganisms that are present in the ecosystem called symbiotic consortium bacteria and yeast (SCOBY). The effectiveness of protecting Scotch pine wood samples against decomposition caused by the fungus Coniophora puteana was evaluated. The obtained results confirmed that impregnation of wood with post-culture medium reduces the possibility of decomposition of this wood by the test fungus. The potential biocidal effect of the post-culture medium from SCOBY was attributed to the presence the substances of a potential fungicidal nature, which were synthesized in the culture medium during metabolic processes occurring in the culture. The obtained results encourage further studies on the potential use of metabolites obtained from SCOBY breeding to protect wood against biodegradation.

Alterations of Biochemical Composition of Leaf and Stem of Cowpea (Vigna unguiculata (L.) Walp.) by Colletotrichum destructivum O’Gara in Nigeria

Colletotrichum destructivum during pathogenesis reduced the nutrient values of cowpea leaf and stem. The protein, fat, carbohydrate, fibre contents of the leaf decreased from 34.91%, 5.42%, 43.61% and 19.46% in the uninfected leaf samples to 20.40%, 2.15%, 37.03% and 15.53% in the infected leaf respectively whereas the moisture and ash contents increased by 10.88% and 11.15% in the uninfected leaf sample to 12.51% and 11.24% respectively in the infected leaf samples. The composition of zinc, sodium, magnesium, iron, and potassium in the leaf increased whereas calcium and phosphorous decreased after inoculation with the test fungus. It reduced the protein content from 15.64% in the healthy stem tissue to 12.69% in the infected one, fat from 1.29% to 0.78%, crude fibre from 16.87% to14.62%, and carbohydrate from 31.11% to 25.39%. Also, the fungus caused a reduction of the calcium and phosphorus contents of the healthy stem tissue from 2.09 mg and 326.50 mg to 1.19 mg and 299.10 mg respectively. Infection of the stem with the pathogen led to increasing moisture, potassium, sodium, zinc, iron, and magnesium contents from 11.80%, 230.12 mg, 111. 28 mg, 1.66 mg, 0.89 mg and 0.95 mg to 12.65% , 364.21 mg, 203.64 mg, 3.02, 1.52 mg, and 2.18 mg respectively. The average loss of the major nutrients; protein, fat, and carbohydrate was more in the leaf than stem, 34.29% and 18.14% respectively 8 weeks after planting (WAP).

Lantana camara: Phytochemical Analysis and Antifungal Prospective

ABSTRACT: In the current study phytochemical analysis and in vitro antifungal potential of fruits, leaves and stem of Lantana camara L. were studied. The phytochemical analysis indicated the presence of alkaloids, flavonoids, tannins, saponins, glycosides and terpenoids in fruit, stem and leaves of L. camara. The in vitro antifungal activity of fruit, stem and leaves of L. camara was tested against Colletotrichum gloeosporioides Penz. Different concentrations (1-5%) of methanolic extract of all the selected parts of L. camara were applied in vitro against the test fungus. The results of in vitro experiment revealed that higher concentration of methanolic fruit extract (5%) significantly reduced the biomass C. gloeosporioides up to 66%. This effective extract of L. camara was partitioned with n-hexane, chloroform, ethyl acetate and n-butanol. The bioactivity of these fractions was tested against C. gloeosporioides. The trials showed that 0.5% concentration of n-hexane fraction of methanolic fruit extract caused the highest reduction (45%) in the radial colony growth of the test fungus. This effective n-hexane fraction was selected for GC-MS analysis to identify various possible antifungal compounds. Cyclopropane, carboxylic acid, 5-heptonic acid, 2,2-dimethyl1-4-pentenoate and 2-Propyloctahydro-1-benzothiophene were identified as major compounds. This study can be concluded that L. camara fruit comprised of bioactive compounds which possess antifungal activity against C. gloeosporioides.

TLC Profile and Activity Test of Secondary Metabolites Aspergillus flavus “In-Habiting” Queen Termite’s Nest Macrotermes gilvus on Enriched Media

Antibiotic are secondary metabolites yielded by microbe especially fungus. Previous research succesfull screened four kinds of fungus that live in termites queen’s nest, one of them was Aspergillus flavus. Furthermore, Alen et al (2016g) states that this fungus last to produce metabolite compounds on SDA media which only exist in first and second subculture extract, omit gradually for the next culture. It was presumed happen caused a different habitat to grow. So it is necessary to enrich the media with queen termite nest to get back the initial metabolites. The enrichment was done using four different media concentrations (0.25; 0,50; 0.75 and 1 grams of nest/mL media). The results show that enrichment of 1 gram of nest/mL media provides the most optimum fungus growht. The third subculture of Aspergillus flavus is cultured on enriched media which will become the fourth subculture, this fungus cultured until tenth subculture, do extraction and fracination to each culture. Based on TLC profile analysis, the initial metabolite not yet formed until tenth subculture, but forms six new stain terpenoid compounds. The result of columns chromatography obtained 10 sub-faction. Activity test was done by diffusion method to 12 test bacteria and 3 test fungus. Spot 2,5,6 (Rf 0.84; 0,36; 0,26) inhibit the growth of Pseudomonas aeruginosa ATCC 27853, spot 3,4 (Rf 0.74; 0,52) inhibit the growth of Micrococcus luteus ATCC 10240. The use of enriched media affect formation of secondary metabolites Aspergillus flavus. Keyword : Secondary metabolites, Aspergillus flavus, Macrotermes gilvus Hagen., Enriched media, TLC Profiles, Activity Assay

BIOEFFICACY OF A COMMON WEED Datura metel AGAINST Colletotrichum gloeosporioides

ABSTRACT Mango (Mangifera indica) is one of the most important trees grown mainly in the tropical and subtropical countries. Anthracnose disease caused by Colletotrichum gloeosporioides, is the most damaging disease causing reduction of flower set and yield losses in mango. The present study was designed to evaluate antifungal activity of Datura metel extracts against C. gloeosporioides. Extracts (1% to 3%) of different parts of D. metel viz. leaves, seeds and roots were assessed for their antifungal potential. Methanolic seed extract of D. metel depicted the highest antifungal potential against the test fungus. All the applied concentrations effectively reduced growth of the test fungus. However, 1.5% conc. of methanolic seeds extract showed maximum reduction (80%) in comparison with control. This extract was further subjected to fractionation using various organic solvents viz. n-hexane, chloroform, ethyl acetate and n-butanol. Chloroform fraction was proved to be the best for the inhibition of the target fungus that was analyzed by GC-MS and various bioactive constituents like n-hexadecanoic acid, phytol, octadecanoic acid, oleic acid, o-xylene and cyclohexanol were identified.