Marvellous Muscodor spp.: Update on Their Biology and Applications.

Nearly 20 years ago, the first report appeared on the discovery of a novel genus-Muscodor. This organism was isolated as an endophyte from a cinnamon tree that had been introduced to Honduras from Sri Lanka in the early part of the last century. Characteristically, the original Muscodor albus, and all of its species isolated since that time are non-spore producers and each one exudes a characteristic spectrum of volatile bioactive compounds. The majority have a whitish mycelium, which is sometimes coiling, intertwined and decorated with variously shaped structures. Presently, there are at least 22 type species known/documented and each has been described as an endophyte from various plant families with widely varying habitats. An enormous variety of volatile organic compounds (VOCs) are produced by Muscodor spp. and some of these include esters, acids, aldehydes, ketones, aromatics, alkanes, alcohols, nitrosamides and terpenoids. The VOCs are both inhibitory and lethal to a wide variety of fungi and bacteria including some major pathogens of plants and humans. Interestingly, in almost all cases studied, no one compound by itself can mimic the bioactivity of the complete gas mixture, suggesting that the volatiles are acting in a synergistic manner and this has been tested with individual as well as the VOCs in various mixtures and concentrations. This review will discuss some of the recent findings in all aspects of this unique fungal genus whilst at the same time pointing out some of the major questions that remain about its biology, ecology and its applications in agriculture, medicine and other sectors. Most importantly, the authors provide arguments supporting the claim that Muscodor is taxonomically distinct from Induratia, a recently proposed change to its nomenclature.

An Insight into the Secondary Metabolism of Muscodor yucatanensis: Small-Molecule Epigenetic Modifiers Induce Expression of Secondary Metabolism-Related Genes and Production of New Metabolites in the Endophyte.

Muscodor spp. are proficient producers of bioactive volatile organic compounds (VOCs) with many potential applications. However, all members of this genus produce varying amounts and types of VOCs which suggests the involvement of epigenetics as a possible explanation. The members of this genus are poorly explored for the production of soluble compounds (extrolites). In this study, the polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes from an endophyte, Muscodor yucatanensis Ni30, were cloned and sequenced. The PKS genes belonged to reduced, partially reduced, non-reduced, and highly reduced subtypes. Strains over-expressing PKS genes were developed through the use of small-molecule epigenetic modifiers (suberoylanilide hydroxamic acid (SAHA) and 5-azacytidine). The putative epigenetic variants of this organism differed considerably from the wild type in morphological features and cultural characteristics as well as metabolites that were produced. Each variant produced a different set of VOCs distinct from the wild type, and several VOCs including methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)hexane-2,4-diol and 2-carboxymethyl-3-n-hexylmaleic appeared in the variant strains, the production of which could be attributed to the activity of otherwise silent PKS genes. The bioactive extrolite brefeldin A was isolated and characterized from the wild type. However, this metabolite was not detected in EV-1, but instead, two other products were isolated and characterized as ergosterol and xylaguaianol C. Hence, M. yucatanensis has the genetic potential to produce several previously undetectable VOCs and organic solvent soluble products. It is also the case that small-molecule epigenetic modifiers can be used to produce stable variant strains of fungi with the potential to produce new molecules. Finally, this work hints to the prospect that the epigenetics of an endophytic microorganism can be influenced by any number of environmental and chemical factors associated with its host plant which may help to explain the enormous chemical diversity of secondary metabolic products found in Muscodor spp.

Characterization of an Endophytic Gloeosporium sp. and Its Novel Bioactivity with "Synergistans".

Gloeosporium sp. (OR-10) was isolated as an endophyte of Tsuga heterophylla (Western hemlock). Both ITS and 18S sequence analyses indicated that the organism best fits either Hypocrea spp. or Trichoderma spp., but neither of these organisms possess conidiophores associated with acervuli, in which case the endophytic isolate OR-10 does. Therefore, the preferred taxonomic assignment was primarily based on the morphological features of the organism as one belonging to the genus Gloeosporium sp. These taxonomic observations clearly point out that limited ITS and 18S sequence information can be misleading when solely used in making taxonomic assignments. The volatile phase of this endophyte was active against a number of plant pathogenic fungi including Phytophthora palmivora, Rhizoctonia solani, Ceratocystis ulmi, Botrytis cinerea, and Verticillium dahliae. Among several terpenes and furans, the most abundantly produced compound in the volatile phase was 6-pentyl-2H-pyran-2-one, a compound possessing antimicrobial activities. When used in conjunction with microliter amounts of any in a series of esters or isobutyric acid, an enhanced inhibitory response occurred with each test fungus that was greater than that exhibited by Gloeosporium sp. or the compounds tested individually. Compounds behaving in this manner are hereby designated "synergistans." An expression of the "median synergistic effect," under prescribed conditions, has been termed the mSE50. This value describes the amount of a potential synergistan that is required to yield an additional median 50% inhibition of a target organism. In this report, the mSE50s are reported for a series of esters and isobutyric acid. The results indicated that isoamyl acetate, allyl acetate, and isobutyric acid generally possessed the lowest mSE50 values. The value and potential importance of these microbial synergistic effects to the microbial environment are also discussed.

Methods of discovery and techniques to study endophytic fungi producing fuel-related hydrocarbons.

One promising area in the search for renewable bio-fuels is the discovery of microorganisms that produce fuel-related hydrocarbons (mycodiesel) that is in stark contrast to yeast fermentation that utilizes expensive sugars or starch to produce ethanol, which is a proven and useful source of fuel, but by no means is it ideal. Recently, a number of endophytic fungi have been isolated and described that make compounds such as mono- terpenoids, alkanes, cyclohexanes, cyclopentanes, and alkyl alcohols/ketones, benzenes and polyaromatic hydrocarbons. Many of these compounds are either identical to or are closely related to those specific classes of molecules that are found in diesel. Most importantly, these organisms make hydrocarbons while utilizing cellulosic polymers found in all plant-based agricultural wastes. Also discussed are some novel methods and techniques to quantitatively and qualitatively study hydrocarbon production by these microbes. Two models are discussed for identifying potential fuel-related compounds, scaling up production of them and advanced engine testing. Finally, it seems possible that endophytic fungi may have an additional attribute of having contributed to the formation of crude oil in the first place and a description of the paleobiosphere, to test this hypothesis, is in this review.

Collophora aceris, a novel antimycotic producing endophyte associated with Douglas Maple.

A novel endophyte designated Collophora aceris, was obtained from stem tissues of Douglas Maple (Acer glabrum var. douglasii) in a Pacific Northwest temperate rainforest. Colonies were slow growing, white, creamy, moist, and translucent to opaque on potato dextrose agar and other media with few aerial hyphae. It also produced solid, dark sclerotia (200-400 µm) on oatmeal agar and no evidence of pseudopycnidia as per other Collophora spp. Conidia were rod-like in the size ranging from 2.2-8.4 × 0.8-1.8 µm and produced holoblastically on conidiogenous cells by budding with no collarette at the budding site. Phylogenetic analyses, based on 18S rDNA sequence data, showed that C. aceris possessed 99 % similarity to other Collophora spp. However, ITS-5.8S rDNA sequence data indicated that the organism was potentially related to Allantophomopsis spp. Finally, combined morphological, physiological, and molecular genetics data indicated that this organism is most like Collophora spp. but it is distinctly unique when compared to all other fungi in this group. It is to be noted that this is the first report of any member of this genus existing as an endophyte. This fungus makes a wide spectrum antimycotic agent (Collophorin) with biological activity against such pathogenic fungi as Pythium ultimum, Phytophthora cinnamomi, Phytophthora palmivora, and Rhizoctonia solani. Collophorin was purified to homogeneity and shown to have a unique mass of 120.0639, an empirical formula of C8H8O1, and UV absorption bands at 260 and 378 nm. This work also indicates that C. aceris possesses the biological potential to provide protection of its host against an array of common plant pathogens.

(6S*)-6-[(1S*,2R*)-1,2-Di-hydroxy-pent-yl]-4-meth-oxy-5,6-di-hydro-2H-pyran-2-one.

The title compound, C11H18O5, was isolated from a liquid culture of Pestalotiopsis sp. In the mol-ecule, the pyran-2-one ring assumes a half-chair conformation. The two terminal C atoms of the pentyl group were refined as disordered over two sets of sites, with refined occupancies of 0.881 (10) and 0.119 (10). In the crystal, mol-ecules are linked via O-H⋯O hydrogen bonds forming a three-dimensional network.

Modulation of volatile organic compound formation in the Mycodiesel-producing endophyte Hypoxylon sp. CI-4.

An endophytic Hypoxylon sp. (strain CI-4) producing a wide spectrum of volatile organic compounds (VOCs), including 1,8-cineole, 1-methyl-1,4-cyclohexadiene and cyclohexane, 1,2,4-tris(methylene), was selected as a candidate for the modulation of VOC production. This was done in order to learn if the production of these and other VOCs can be affected by using agents that may modulate the epigenetics of the fungus. Many of the VOCs made by this organism are of interest because of their high energy densities and thus the potential they might have as Mycodiesel fuels. Strain CI-4 was exposed to the epigenetic modulators suberoylanilide hydroxamic acid (SAHA, a histone deacetylase) and 5-azacytidine (AZA, a DNA methyltransferase inhibitor). After these treatments the organism displayed striking cultural changes, including variations in pigmentation, growth rates and odour, in addition to significant differences in the bioactivities of the VOCs. The resulting variants were designated CI4-B, CI4-AZA and CI4-SAHA. GC/MS analyses of the VOCs produced by the variants showed considerable variation, with the emergence of several compounds not previously observed in the wild-type, particularly an array of tentatively identified terpenes such as α-thujene, sabinene, γ-terpinene, α-terpinolene and ß-selinene, in addition to several primary and secondary alkanes, alkenes, organic acids and derivatives of benzene. Proton transfer reaction mass spectroscopic analyses showed a marked increase in the ratio of ethanol (mass 47) to the total mass of all other ionizable VOCs, from ~0.6 in the untreated strain CI-4 to ~0.8 in CI-4 grown in the presence of AZA. Strain CI4-B was created by exposure of the fungus to 100 µM SAHA; upon removal of the epigenetic modulator from the culture medium, it did not revert to the wild-type phenotype. Results of this study have implications for understanding why there may be a wide range of VOCs found in various isolates of this fungus in nature.

In vitro antimicrobial activity of volatile organic compounds from Muscodor crispans against the pathogenic oomycete Pythium insidiosum.

Pythium insidiosum is an oomycete capable of causing a life-threatening disease in humans, called pythiosis. Conventional antifungal drugs are ineffective against P. insidiosum infection. A synthetic mixture of the volatile organic compounds (VOCs) from the endophytic fungus Muscodor crispans strain B23 demonstrates antimicrobial effects against a broad range of human and plant pathogens, including fungi, bacteria, and oomycetes. We studied the in vitro effects of B23 VOCs against 25 human, 1 animal, and 4 environmental isolates of P. insidiosum, compared with a no-drug control. The B23 synthetic mixture, at amounts as low as 2.5 microl, significantly reduced growth of all P. insidiosum isolates by at least 80%. The inhibitory effect of the B23 VOCs was dose-dependent. The growth of all isolates was completely inhibited by a dose of 10.0 microl of B23 VOCs, and all isolates were killed by a dose of 20.0 microl. Synthetic B23 VOCs of M. crispans had inhibitory and lethal effects against all P. insidiosum isolates tested. Further studies are needed to evaluate this mixture for treatment of pythiosis.

An endophytic Phomopsis sp. possessing bioactivity and fuel potential with its volatile organic compounds.

An unusual Phomopsis sp. was isolated as endophyte of Odontoglossum sp. (Orchidaceae), associated with a cloud forest in Northern Ecuador. This fungus produces a unique mixture of volatile organic compounds (VOCs) including sabinene (a monoterpene with a peppery odor) only previously known from higher plants. In addition, some of the other more abundant VOCs recorded by GC/MS in this organism were 1-butanol, 3-methyl; benzeneethanol; 1-propanol, 2-methyl and 2-propanone. The gases of Phomopsis sp. possess antifungal properties and an artificial mixture of the VOCs mimicked the antibiotic effects of this organism with the greatest bioactivity against a wide range of plant pathogenic test fungi including: Pythium, Phytophthora, Sclerotinia, Rhizoctonia, Fusarium, Botrytis, Verticillium, and Colletotrichum. The IC(50) values for the artificial gas mixture of Phomopsis sp. varied between 8 and 25.65 µl/mL. Proton transfer reaction-mass spectrometry monitored the concentration of VOCs emitted by Phomopsis sp. and yielded a total VOC concentration of ca. 18 ppmv in the head space at the seventh day of incubation at 23°C on PDA. As with many VOC-producing endophytes, this Phomopsis sp. did survive and grow in the presence of the inhibitory gases of Muscodor albus. A discussion is presented on the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship.

The diversity and anti-microbial activity of endophytic actinomycetes isolated from medicinal plants in Panxi plateau, China.

Traditional Chinese medicinal plants are sources of biologically active compounds, providing raw material for pharmaceutical, cosmetic and fragrance industries. The endophytes of medicinal plants participate in biochemical pathways and produce analogous or novel bioactive compounds. Panxi plateau in South-west Sichuan in China with its unique geographical and climatological characteristics is a habitat of a great variety of medicinal plants. In this study, 560 endophytic actinomycetes were isolated from 26 medicinal plant species in Panxi plateau. 60 isolates were selected for 16S rDNA-RFLP analysis and 14 representative strains were chosen for 16S rDNA sequencing. According to the phylogenetic analysis, seven isolates were Streptomyces sp., while the remainder belonged to genera Micromonospora, Oerskovia, Nonomuraea, Promicromonospora and Rhodococcus. Antimicrobial activity analysis combined with the results of amplifying genes coding for polyketide synthetase (PKS-I, PKS-II) and nonribosomal peptide synthetase (NRPS) showed that endophytic actinomycetes isolated from medicinal plants in Panxi plateau had broad-spectrum antimicrobial activity and potential natural product diversity, which further proved that endophytic actinomycetes are valuable reservoirs of novel bioactive compounds.

Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus.

Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.

Hypoxylon sp., an endophyte of Persea indica, producing 1,8-cineole and other bioactive volatiles with fuel potential.

An endophytic fungus of Persea indica was identified, on the basis of its anamorphic stage, as Nodulosporium sp. by SEM. Partial sequence analysis of ITS rDNA revealed the identity of the teleomorphic stage of the fungus as Hypoxylon sp. It produces an impressive spectrum of volatile organic compounds (VOCs), most notably 1,8-cineole, 1-methyl-1,4-cyclohexadiene, and tentatively identified (+)-.alpha.-methylene-.alpha.-fenchocamphorone, among many others, most of which are unidentified. Six-day-old cultures of Hypoxylon sp. displayed maximal VOC-antimicrobial activity against Botrytis cinerea, Phytophthora cinnamomi, Cercospora beticola, and Sclerotinia sclerotiorum suggesting that the VOCs may play some role in the biology of the fungus and its survival in its host plant. Media containing starch- or sugar-related substrates best supported VOC production by the fungus. Direct on-line quantification of VOCs was measured by proton transfer mass spectrometry covering a continuous range with optimum VOC production occurred at 6 days at 145 ppmv with a rate of production of 7.65 ppmv/h. This report unequivocally demonstrates that 1,8-cineole (a monoterpene) is produced by a microorganism, which represents a novel and important source of this compound. This monoterpene is an octane derivative and has potential use as a fuel additive as do the other VOCs of this organism. Thus, fungal sourcing of this compound and other VOCs as produced by Hypoxylon sp. greatly expands their potential applications in medicine, industry, and energy production.

Multiple, novel biologically active endophytic actinomycetes isolated from upper Amazonian rainforests.

Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants.

Javanicin, an antibacterial naphthaquinone from an endophytic fungus of neem, Chloridium sp.

The endophytic fungus Chloridium sp. produces javanicin under liquid and solid media culture conditions. This highly functionalized naphthaquinone exhibits strong antibacterial activity against Pseudomonas spp., representing pathogens to both humans and plants. The compound was crystallized and the structure was elucidated by X-ray crystallography. The X-ray structure confirms the previously elucidated structure of the compound that was done under standard spectroscopic methods. The importance of javanicin in establishing symbiosis between Chloridium sp. and its host plant, Azadirachta indica, is briefly discussed.

Synergism among volatile organic compounds resulting in increased antibiosis in Oidium sp.

Oidium sp. has been recovered as an endophyte in Terminalia catappa (tropical chestnut) in Costa Rica. The volatile organic compounds (VOCs) of this organism uniquely and primarily consist of esters of propanoic acid, 2-methyl-, butanoic acid, 2-methyl-, and butanoic acid, 3-methyl-. The VOCs of Oidium sp. are slightly inhibitory to many plant pathogenic fungi. Previous work on the VOCs of Muscodor albus demonstrated that besides esters of small organic acids, a small organic acid and a naphthalene derivative were needed to obtain maximum antibiotic activity. Thus, the addition of exogenous volatile compounds such as isobutyric acid and naphthalene, 1,1'-oxybis caused a dramatic synergistic increase in the antibiotic activity of the VOCs of Oidium sp. against Pythium ultimum. In fact, at elevated concentrations, there was not only 100% inhibition of P. ultimum but killing as well. In addition, a coculture of Muscodor vitigenus (making only naphthalene) and Oidium sp. plus isobutyric acid produced an additive antibiosis effect against P. ultimum. The biological implications of multiple volatile compounds acting to bring about antibiosis in nature are discussed.

Purification, identification and activity of phomodione, a furandione from an endophytic Phoma species.

Phomodione, [(4aS(*),9bR(*))-2,6-diacetyl-7-hydroxy-4a,9-dimethoxy-8,9b-dimethyl-4a.9b-dihydrodibenzo[b,d]furan-1,3(2H,4H)-dione], an usnic acid derivative, was isolated from culture broth of a Phoma species, discovered as an endophyte on a Guinea plant (Saurauia scaberrinae). It was identified using NMR, X-ray crystallography, high resolution mass spectrometry, as well as infrared and Raman spectroscopy. In addition to phomodione, usnic acid and cercosporamide, known compounds with antibiotic activity, were also found in the culture medium. Phomodione exhibited a minimum inhibitory concentration of 1.6 microg/mL against Staphylococcus aureus using the disk diffusion assay, and was active against a representative oomycete, ascomycete and basidiomycete at between three and eight micro-grams per mL.

Microbial Flora Associated with the Halophyte-Salsola imbricate and Its Biotechnical Potential.

Halophytes are associated with the intertidal forest ecosystem of Saudi Arabia and seemingly have an immense potential for yielding useful and important natural products. In this study we have aimed to isolate and characterize the endophytic and rhizospheric bacterial communities from the halophyte, Salsola imbricata, In addition these bacterial strains were identified and selected strains were further studied for bioactive secondary metabolites. At least 168 rhizspheric and endophytic bacteria were isolated and of these 22 were active antagonists against the oomycetous fungal plant pathogens, Phytophthora capsici and Pythium ultimum. Active cultures were mainly identified with molecular techniques (16S r DNA) and this revealed 95.7-100% sequence similarities with relevant type strains. These microorgansims were grouped into four major classes: Actinobacteria, Firmicutes, ß-Proteobacteria, and γ-Proteobacteria. Production of fungal cell wall lytic enzymes was detected mostly in members of Actinobacteria and Firmicutes. PCR screening for type I polyketide synthases (PKS-I), type II polyketide synthases (PKS-II) and nonribosomal peptide synthetases (NRPS) revealed 13 of the 22 strains (59%) were positive for at least one of these important biosynthetic genes that are known to be involved in the synthesis of important antibiotics. Four bacterial strains of Actinobacteria with potential antagonistic activity including two rhizobacteria, EA52 (Nocardiopsis sp.), EA58 (Pseudonocardia sp.) and two endophytic bacteria Streptomyces sp. (EA65) and Streptomyces sp. (EA67) were selected for secondary metabolite analyses using LC-MS. As a result, the presence of different bioactive compounds in the culture extracts was detected some of which are already reported for their diverse biological activities including antibiotics such as Sulfamethoxypyridazine, Sulfamerazine, and Dimetridazole. In conclusion, this study provides an insight into antagonistic bacterial population especially the Actinobacteria from S. imbricata, producing antifungal metabolites of medical significance and characterized taxonomically in future.

Bioactive endophytic streptomycetes from the Malay Peninsula.

Three novel endophytic streptomycetes have been isolated and characterized from plants with ethnobotanical uses on the Malay Peninsula including: Thottea grandiflora (family -Aristolochiaceae), Polyalthia spp. (family -Annonaceae), and Mapania sp. (family -Cyperaceae). Each isolate, as studied by scanning electron microscopy, has small hyphae, and produces typical barrel-shaped spores arising by hyphal fragmentation. Interestingly, although none has any detectable antibacterial killing properties, each has demonstrable killing activity against one or more pathogenic fungi including organisms such as Phytophthora erythroseptica, Pythium ultimum, Sclerotinia sclerotiorum, Mycosphaerella fijiensis and Rhizoctonia solani. Molecular biological studies on the rRNA gene sequence of each isolate revealed that it is distinct from all other genetic accessions of streptomyectes in GenBank, and each bears some genetic similarity to other streptomycetes. The bioactivity of each microbe was extractable in various organic solvents.

Functional Characterization of Endophytic Fungal Community Associated with Oryza sativa L. and Zea mays L.

In a natural ecosystem, the plant is in a symbiotic relationship with beneficial endophytes contributing huge impact on its host plant. Therefore, exploring beneficial endophytes and understanding its interaction is a prospective area of research. The present work aims to characterize the fungal endophytic communities associated with healthy maize and rice plants and to study the deterministic factors influencing plant growth and biocontrol properties against phytopathogens, viz, Pythium ultimum, Sclerotium oryzae, Rhizoctonia solani, and Pyricularia oryzae. A total of 123 endophytic fungi was isolated using the culture-dependent approach from different tissue parts of the plant. Most dominating fungal endophyte associated with both the crops belong to genus Fusarium, Sarocladium, Aspergillus, and Penicillium and their occurrence was not tissue specific. The isolates were screened for in vitro plant growth promotion, stress tolerance, disease suppressive mechanisms and based on the results, each culture from both the cereal crops was selected for further study. Acremonium sp. (ENF 31) and Penicillium simplicisssum (ENF22), isolated from maize and rice respectively could potentially inhibit the growth of all the tested pathogens with 46.47 ± 0.16 mm to 60.09 ± 0.04 mm range zone of inhibition for ENF31 and 35.48 ± 0.14 to 62.29 ± 0.15 mm for ENF22. Both significantly produce the defensive enzymes, ENF31 could tolerate a wide range of pH from 2 to 12, very important criteria, for studying plant growth in different soil types, especially acidic as it is widely prevalent here, making more land unsuitable for cultivation. ENF22 grows in pH range 3-12, with 10% salt tolerating ability, another factor of consideration. Study of root colonization during 7th to 30th days of growth phase reveals that ENF31 could colonize pleasantly in rice, though a maize origin, ranging from 1.02 to 1.21 log10 CFU/g root and in maize, it steadily colonizes ranging from 0.95 to 1.18 log10 CFU, while ENF22 could colonize from 0.98 to 1.24 Log10CFU/g root in rice and 1.01 to 1.24Log10CFU/g root in maize, just the reverse observed in Acremonium sp. Therefore, both the organism has the potency of a promising Bio-resource agent, that we must definitely explore to fill the gap in the agriculture industry.

Munumbicins E-4 and E-5: novel broad-spectrum antibiotics from Streptomyces NRRL 3052.

Streptomyces NRRL 30562 was originally isolated as an endophyte from Kennedia nigriscans, snakevine, in the Northern Territory of Australia. This plant has been used for centuries by Aboriginal peoples to treat open bleeding wounds to prevent sepsis. A solvent extract of the crude fluid from cultures of this endophyte possesses wide-spectrum antibiotic activity. Some of the bioactivity is associated with the appearance of actinomycins X2, D, and Xobeta, the first two of which had been previously designated munumbicins A and B, respectively. Other novel compounds bearing wide-spectrum antibiotic activity are also produced by Streptomyces NRRL 30562, and these are designated munumbicins E-4 and E-5. Mass spectrometric analyses of these peptide antibiotics show that they have identical masses (1445.00) but different retention times on HPLC. Both compounds showed activity against gram-positive and gram-negative bacteria. The plant pathogenic fungus, Pythium ultimum is sensitive to both munumbicins at 5.0 microg mL(-1) The malarial parasite, Plasmodium falciparum has IC50 values of 0.50+/-0.08 and 0.87+/-0.0.26 microg mL(-1) for E-4 and E-5, respectively. It appears that other bioactive compounds, related to E-4 and E-5, are also produced making it the most biologically active endophytic Streptomyces spp. on record.