1.Ameliorative effect of plant growth promoting bacterial endophyte Pantoea agglomerans on salt stress at early stage of growth in rice
Chai Jun Ching ; Subramanian Deivanai
Malaysian Journal of Microbiology 2015;11(4):341-351
Aims: Endophytes are known to impart tolerance to crop plants; hence the study was initiated to evaluate some plant
growth promoting endophytic bacteria isolated from rice and maize for salt tolerance in rice.
Methodology and results: A total of 31 endophytic bacteria were screened for growth promoting characteristics on the
basis of phosphate solubilization, nitrogen fixation, Indole acetic acid biosynthesis, production of ammonium, protease
and cellulase. Only 2 Bacillus species and Pantoea agglomerans were positive for all growth characteristics and
subsequently inoculated with rice seeds under controlled as well as in saline condition (NaCl) in order to evaluate the
plant growth promoting (PGP) ability on the basis of germination rate and seedling vigor. The seedling grown under
control condition, significantly alter the growth parameters such as germination rate, root and shoot length, fresh and dry
weight along with seedling vigor index. Under saline condition, the genus Bacillus and Pantoea invariably counteracted
the effect of stress; however, P. agglomerans showed significant differences for shoot length, fresh and dry weight.
Analysis of correlation coefficient exhibited positive and strong association of seedling vigor index with dry weight and
rate of germination, thereby revealing the interdependency of the traits under stress.
Conclusion, significance and impact of study: The study confirmed a mutualistic interaction of P. agglomerans with
the host plant rice and leads to enhanced growth of the host under salt stress condition.
Endophytes
;
Bacillus
2.Evaluation of the biocontrol potential of endophytic bacteria isolated from Coffea liberica (w. Bull ex hiern) against brown eyespot-causing fungal phytopathogen
Gary Antonio C. Lirio ; Anna Beatriz A. Suavengco ; Kathleen Chloie C. Antonio ; John Eric P. Aggarao ; Janeth G. Mamansag
Malaysian Journal of Microbiology 2020;16(6):477-490
Aims:
The study aims to investigate the potential of the endophytic bacteria as an alternative to control the devastating
brown eyespot disease caused by Cercospora sp. in coffee plants. The fungal phytopathogen causes severe leaf fall
and berry damages resulting in serious yield losses in coffee farms in the Philippines and worldwide. Currently, the
management of this fungal infection relies heavily on synthetic fungicides, which may be of major environmental
concern.
Methodology and results:
Endophytic bacteria were isolated from the intercellular tissues of Coffea liberica leaves by
surface sterilization, maceration, dilution technique, plating on trypticase soy agar and colony characterization.
Fourteen isolated endophytic bacteria were screened for their ability to inhibit the mycelial growth of Cercospora sp.
through modified dual culture assay. Isolates HCC10-3SC3, HCC10-3SC2, HCC10-1SC1, ICC10-3SC1, and ICC10-1SC1
yielded the highest percent inhibition of radial growth (PIRG) with 59.56%, 60.92%, 60.96%, 64.36%, and 67.06%
respectively and are statistically significant (p<0.05) compared to the antibiotic control nystatin. The top five performing
endophytic bacteria were subjected to hydrolytic enzyme production assays and found to exhibit amylolytic, lipolytic,
proteolytic, chitinolytic, and cellulolytic activities. Based on the morphological and molecular identification by the 16S
rRNA sequence analysis, isolates showed the similarity with Staphylococcus cohnii, Bacillus siamensis,
Staphylococcus hominis, and Kosakonia cowanii found in GENBANK.
Conclusion, significance and impact of study
The study revealed the biological control potential of endophytic
bacteria agents against the brown eyespot-causing fungus in coffee.
Endophytes--pathogenicity
3.Biocontrol potential of endophytic fungi in tea (Camellia sinensis (L.) Kuntze) leaves against selected fungal phytopathogens
Kasun Thambugala ; Dinushani Daranagama ; Sagarika Kannangara
Malaysian Journal of Microbiology 2022;18(6):665-669
Aims:
Endophytic fungi are a diverse group of microorganisms that stay asymptomatically in the healthy tissues of the host. Many fungal endophytes are associated with the tea plant (Camellia sinensis) and the pathogens of the tea plant have the potential to grow as endophytes or act as latent pathogens during the initial growth of the plant. The present study aimed at screening tea endophytic fungi with the potential for control of a few critical phytopathogens, Fusarium sp., Lasiodiplodia theobromae, Pestalotiopsis sp. and Sclerotinia sclerotiorum while evaluating the efficiency of growth inhibition of these phytopathogens by the endophytic fungal isolates using in vitro assays.
Methodology and results:
Five endophytic fungal strains; Colletotrichum gloeosporioides, C. siamense, Daldinia eschscholtzii, Pseudopestalotiopsis chinensis and Phyllosticta capitalensis isolated from leaves of C. sinensis in Sri Lanka were evaluated for growth inhibition against plant pathogens; Fusarium sp., L. theobromae, Pestalotiopsis sp. and S. sclerotiorum using the dual culture assay and volatile compound-mediated inhibition assay. All the fungal endophytes used in this study exhibited antifungal activity against Fusarium sp., Pestalotiopsis sp. and S. sclerotiorum in the dual culture assay on PDA. Daldinia eschscholtzii (67.30%) and C. gloeosporioides (61.54%) showed strong antagonistic activity against S. sclerotiorum, while P. capitalensis (42.30%) demonstrated moderate activity. All the endophytic fungal strains showed moderate antifungal activities against Fusarium sp. The percentage growth inhibitions of Pestalotiopsis sp. by all the endophytic isolates tested were below 25.00%. In the volatile compound-mediated inhibition assay, none of the endophytic isolates showed visible inhibition against the phytopathogens used.
Conclusion, significance and impact of study
In this study, the fungal endophytes which showed potential antagonistic activity against the tested phytopathogens can be used to develop commercialized products of fungal biocontrol agents (BCAs) for controlling plant fungal diseases.
Endophytes
;
Tea
4.Isolation and morphological identification of endophytic fungi from leaves and stems of Aquilaria malaccensis Lamk. originating from Java Island, Indonesia
Abdul Salim ; Tri Rini Nuringtyas
Malaysian Journal of Microbiology 2023;19(1):55-62
Aims:
Endophytic fungi are the remarkable category of host-associated fungal community that invades the intercellular regions of host tissues, benefiting their host while obtaining an advantage. Fungal endophytes have lately attracted prominence as a source of active secondary metabolites. This investigation aimed to identify fungal endophytes that reside inside the leaves and stems of Aquilaria malaccensis.
Methodology and results:
Healthy A. malaccensis stems and leaves samples were collected. Clean leaves and stems were cut to a size of 1 cm, followed by sterilization using 75% ethanol for 1 min, 3% sodium hypochlorite solution for 1 min, and finally, rinsing with sterile water 3 times for 1 min and drying with sterile paper. The sterile samples were put onto Potato Dextrose Agar (PDA) media containing chloramphenicol for 7-14 days until the mycelium grew for morphological identification under a light microscope. Five endophytic fungi were recovered from leaves, while nine endophytic fungi were obtained from stems. Using morphological approaches, nine of the endophytes had observed to produce conidia fungi, whereas the others did not. Neopestalotiopsis sp., Aspergillus sp., Arthrinium sp., Curvularia sp., Podospora sp., Mucor sp. and Verticillium sp. were identified as nine of the fourteen endophytes.
Conclusion, significance and impact of study
The number of endophytic fungi discovered in different organs varies. Not all endophytic fungi that grow can create sexual phages. Six genera of endophytic fungi were identified.
Endophytes
;
Thymelaeaceae
5.Genome analysis and plant growth promoting activity of Pseudonocardia strain DR1-2 from the root of Dendrobium christyanum Rchb.f.
Nisachon Tedsree ; Kittisak Likhitwitayawuid ; Boonchoo Sritularak ; Somboon Tanasupawat
Malaysian Journal of Microbiology 2022;18(6):629-639
Aims:
The objective of this study was to analyze the genome of endophytic actinomycete associated with orchids and evaluate its plant hormone activities, including phytohormone, siderophore, ammonia production, zinc and phosphate solubilization.
Methodology and results:
Strain DR1-2 isolated from the roots of the Thai orchid, Dendrobium christyanum Rchb.f., was closely related to Pseudonocardia alni DSM 44104T, P. antarctica DSM 44749T and P. carboxydivorans Y8T (99.93-100% similarity) based 16S rRNA gene sequence. This strain exhibited IAA production (294.10 ± 12.17 μg/mL), phosphate solubilization (2.20 ± 0.08 solubilization Index, SI), positive for siderophore production and ammonia production (36.99 ± 2.24 μg/mL). It showed a maximum IAA of 489.73 ± 8.90 μg/mL, when optimized using 0.5% Ltryptophan, pH 6 and incubated at 30 °C for 7 days. The IAA of strain enhanced the root length, shoot length, number of roots and fresh weight of rice seedlings (Oryza sativa L. cv. RD49). The draft genome of strain DR1-2 was 6,077,423 bp in 23 contigs with G+C content of 74.6%. The average nucleotide identity-Blast (ANIb) and average nucleotide identity-MUMmer (ANIm) values of strain DR1-2 and related type strains were 95.81 to 97.25% and the digital DNA-DNA hybridization (dDDH) values were 72.60 to 74.00%, respectively. Genomic analysis of strain DR1-2 revealed that the gene encodes the enzyme involved in the phytohormones biosynthesis and gene clusters involved in the biosynthesis of bioactive metabolites.
Conclusion, significance and impact of study
Endophytic actinomycete, Pseudonocardia strain DR1-2 from Thai orchid, D. christyanum Rchb.f., exhibited significant IAA production and affected the growth of the plant, which was the potential source of plant hormones for agricultural applications.
Endophytes
;
Actinobacteria
;
Pseudonocardia
6.Two Species of Endophytic Penicillium from Pinus rigida in Korea.
Chang Sun KIM ; Myung Soo PARK ; Seung Hun YU
Mycobiology 2008;36(4):222-227
Upon studying the diversity of fungal endophytes associated with pine trees in Korea, many species of Penicillium were encountered. In this study, we report two species of Penicillium isolated from the needles of Pinus rigida. Based on ID region analysis, cultural and morphological characteristics, the two species were identified as Penicillium fellutanum and P. toxicarium, both of which are new to Korea.
Endophytes
;
Korea
;
Needles
;
Penicillium
;
Pinus
7.Antimicrobial activities of endophytic fungi residing in Aloe vera against diabetic wound pathogens
Md Abu Taher ; Tong Woei Yenn ; Leong Chean Ring ; Suzana Wahidin ; Mohd Azizan Mohd Noor ; Syarifah Ab Rashid ; Tan Wen-Nee
Malaysian Journal of Microbiology 2020;16(6):519-529
Aims:
Endophytic fungi are organisms that colonize living plant tissues without causing significant symptoms of
diseases. They are known as the repository of bioactive compounds. This study was aimed to isolate endophytic fungi
associated with Aloe vera and to assess their antimicrobial activity against the diabetic wound pathogens that result to
lower limb amputations.
Methodology and results:
In this study, 84 endophytic fungi were isolated from A. vera by using 5% sodium
hypochlorite and 70% ethanol as surface sterilants. On preliminary antimicrobial screening by agar plug assay, 12
(14.3%) isolates showed significant antagonistic activity on the test microorganisms. Two of the endophytes were
identified as Aspergillus flavus and Colletotrichum gloeosporioides through morphological and molecular techniques.
The fungal cultures fermented in shake flask were extracted subsequently with hexane, dichloromethane, ethyl acetate,
and n-butanol. Ethyl acetate and dichloromethane extracts of A. flavus and C. gloeosporioides inhibited all test bacteria.
The compounds in the extracts were seemed to be semi-polar in nature. On broth microdilution assay, minimal inhibitory
and minimal lethality concentration of ethyl acetate extracts of the fungi were found in the range of 0.63−2.50 and
1.25−5.00 mg/mL, respectively.
Conclusion, significance and impact of study
This study reveals that A. vera harbours a wide diversity of endophytic
fungi. A. flavus and C. gloeosporioides showing broad spectrum antimicrobial activity on wound pathogens may be
potential sources of bioactive compounds. Further investigations should be conducted to isolate and identify the
antimicrobial compound produced by these fungal isolates.
Endophytes--isolation &
;
purification
;
Aloe
8.Identification and characterization of plant growth-promoting properties of bacterial endophytes from selected Zingiberaceae plants
Kingchan Malisorn ; Sirinapa Kabbun ; Sukanya Phuengjayaem ; Pawina Kanchanasin ; Somboon Tanasupawat
Malaysian Journal of Microbiology 2021;17(5):548-559
Aims:
This study aims to isolate, characterize and screen the plant growth-promoting bacteria from Zingiberaceae plants. Plant promoting activities such as indole-3-acetic acid (IAA), phosphate solubilization, zinc solubilization and nitrogen-fixing capabilities are determined, and the IAA production of selected isolates are optimized.
Methodology and results:
Endophytic bacteria were isolated from the plant samples by surface sterilization on nutrient agar (NA) plates and incubated at 30 °C for 2-3 days. The bacteria were identified based on their phenotypic characteristics and 16S rRNA gene sequence analyses. All isolates were identified as genera Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella. The isolates exhibited phosphate solubilization (1.5 ± 0.75-37.5 ± 8.75 Solubilization Index, SI), zinc solubilization (2.5 ± 0-60 ± 1.5 SI) and IAA production (0.1 ± 0.2-115.7 ± 1.6 µg/mL), while 3 isolates possessed nitrogen-fixing capabilities. Five isolates (PHAS-2, PWS-2, PWR-2, PHBS-2 and SCG-2) were selected for IAA optimization. Isolate PWR-2 produced the maximum IAA at 447.7 ± 0 µg/mL when tryptophan concentration was maintained at 1.0%.
Conclusion, significance and impact of study
Genera of bacteria included Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella were successfully isolated from Zingiberaceae plants. All the isolates showed the capability to produce IAA, while some isolates exhibited phosphate solubilization and zinc solubilization, and a few possessed nitrogen-fixing capabilities. The potential IAA production isolates could be applied for the enhancement of agricultural production that will be becoming a more widely accepted practice.
Plant Growth Regulators
;
Endophytes
;
Zingiberaceae
9.Diversity and Bioactive Potential of Culturable Fungal Endophytes of Medicinal Shrub Berberis aristata DC.: A First Report.
Supriya SHARMA ; Suruchi GUPTA ; Manoj K DHAR ; Sanjana KAUL
Mycobiology 2018;46(4):370-381
Bioactive natural compounds, isolated from fungal endophytes, play a promising role in the search for novel drugs. They are an inspiring source for researchers due to their enormous structural diversity and complexity. During the present study fungal endophytes were isolated from a well-known medicinal shrub, Berberis aristata DC. and were explored for their antagonistic and antioxidant potential. B. aristata, an important medicinal shrub with remarkable pharmacological properties, is native to Northern Himalayan region. A total of 131 endophytic fungal isolates belonging to eighteen species and nine genera were obtained from three hundred and thirty surface sterilized segments of different tissues of B. aristata. The isolated fungi were classified on the basis of morphological and molecular analysis. Diversity and species richness was found to be higher in leaf tissues as compared to root and stem. Antibacterial activity demonstrated that the crude ethyl acetate extract of 80% isolates exhibited significant results against one or more bacterial pathogens. Ethyl acetate extract of Alternaria macrospora was found to have potential antibacterial activity. Significant antioxidant activity was also found in crude ethyl acetate extracts of Alternaria alternata and Aspergillus flavus. Similarly, antagonistic activity of the fungal endophytes revealed that all antagonists possessed inhibition potential against more than one fungal pathogen. This study is an important step towards tapping endophytic fungal diversity for bioactive metabolites which could be a step forward towards development of novel therapeutic agents.
Alternaria
;
Aspergillus flavus
;
Berberis*
;
Endophytes*
;
Fungi
10.Diversity and Seasonal Variation of Endophytic Fungi Isolated from Three Conifers in Mt. Taehwa, Korea.
Chang Kyun KIM ; Ju Kyeong EO ; Ahn Heum EOM
Mycobiology 2013;41(2):82-85
The needled leaves of three conifer species were collected in Mt. Taehwa during different seasons of the year. Total 59 isolates and 19 species of endophytic fungi were isolated from the leaves and identified using morphological and molecular characteristics. As a result, Shannon index was different in its host plant; Larix kaempferi had a highest value of species diversity. According to the sampling season, 9 species of 19 species were isolated during fall season. The results suggest that the existing of host plant and sampling season are major factors of distribution of endophytic fungi.
Coniferophyta
;
Endophytes
;
Fungi
;
Korea
;
Larix
;
Plants
;
Seasons