scholarly journals Soil Chitinolytic Bacteria from Jambi Province to Produce Antifungal of Plant Pathogens

Mangifera Edu ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 26-37
Author(s):  
Risky Hadi Wibowo ◽  
Sipriyadi Sipriyadi ◽  
Nisa Rachmania Mubarik ◽  
Iman Rusmana

Chitinolytic bacteria are bacteria that have chitinolytic activity, which is able to hydrolysis the composition of chitin which composes many fungal cell walls. Chitinolytic bacteria are currently more widely used because of their ability as a biological control agent to the pathogenic fungi especially in horticultural and plantation crops. This research was conducted with the aim of obtaining isolates of chitinolytic bacteria that were able to inhibit the growth of plant pathogenic fungi in Vitro on chitin agar media. Fusarium oxysporum, Sclerotium rolfsii, and Rhizoctonia solanii are used in the inhibition test of chitinolytic bacteria. Bacteria were isolated and screened from the soil of Bukit Dua Belas National Park and Oil Palm Plantations in Jambi using 0.3% chitin agar media. The results showed that two of 10 bacterial isolates were able to produce inhibition zones to the growth of hyphae of pathogenic fungi on potato dextrose agar (PDA) media. TB04-13 isolate was able to produce the largest inhibition in F. oxysporum and R. solanii about 42% and 42.05% respectively, while TB04-15 isolate produced the biggest inhibition in S. Rolfsii ranged to 25.50%. Based on the chitinolytic index (CI) values, isolates TB04-13 and TB04-15 produced CI values ​​of 1.60 and 0.63, respectively. The morphological characteristics and Gram staining of both TB04-13 and TB04-15 chitinolytic isolates are included in rod-shaped and Gram-positive bacteria. Both of these isolates can be used as antifungal-producing candidates for plant pathogenic fungi in Indonesia.

Elkawnie ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 273
Author(s):  
Risky Hadi Wibowo ◽  
Sipriyadi Sipriyadi ◽  
Nisa Rachmania Mubarik ◽  
Iman Rusmana ◽  
Maggy Thenawidjaya Suhartono

Abstract: Chitinolytic actinobacteria are currently more widely used because of their ability as the biological control agents to the pathogenic fungi, especially in horticultural and plantation crops. This research was conducted to obtain isolates of chitinolytic soil actinobacteria from the rhizosphere of the rubber plant (Hevea brasiliensis) area in IPB University. Antifungal activities from these actinobacteria hopely able to inhibit the growth of plant pathogenic fungi in Vitro on chitin agar media. Fusarium oxysporum and Sclerotium rolfsii are used in the inhibition test of chitinolytic actinobacteria. The results successfully obtained 16 isolates of actinobacteria were grew on  Humic Acid Vitamin (HV) agar. It showed that six of 16 actinobacteria isolates were able to produce inhibition zones to the growth of hyphae of pathogenic fungi on potato dextrose agar (PDA). KK-15 and KK-07 isolates were able to produce the largest inhibition percentages in F. oxysporum and S. rolfsii. Based on the chitinolytic index (CI) values, KK-15 and KK-07 isolates produced CI values of 1.25 and 1.5, respectively. The morphological characteristics and Gram staining of both KK-15 and KK-07 isolates are closely relative with Streptomyces sp. Abstrak: Bakteri kitinolitik saat ini banyak diteliti karena kemampuannya sebagai agens pengendali hayati jamur patogen khususnya pada tanaman hortikultura dan perkebunan. Penelitian ini dilakukan untuk mendapatkan isolat-isolat bakteri kitinolitik asal tanah dari bagian perakaran tanaman karet (Hevea brasiliensis) di daerah perkebunan karet Institut Pertanian Bogor (IPB). Aktivitas antifungi dari bakteri ini diharapkan  mampu menghambat pertumbuhan jamur patogen tanaman secara in Vitro pada media agar-agar kitin. Fusarium oxysporum dan Sclerotium rolfsii digunakan dalam uji hambat aktinobakteri kitinolitik. Hasil penelitian memperoleh 16 isolat aktinobakteri berhasil diisolasi dengan menggunakan media agar-agar Humic Acid Vitamin (HV), dan dari 16 isolat tersebut, enam isolat mampu menghasilkan zona hambat terhadap pertumbuhan hifa dari kedua jamur patogen pada media Potato Dextrose Agar (PDA) secara in Vitro. Isolat KK-15 dan KK-07 mampu menghasilkan diameter hambatan terbesar pada jamur F. oxysporum dan S. rolfsii. Berdasarkan nilai index kitinolitik (IK), isolat KK-15 dan KK-07 menghasilkan nilai IK sebesar 1,25 dan 1,5 secara berurutan. Karakteristik morfologi dan pewarnaan Gram dari kedua isolat yaitu KK-15 dan KK-07 memiliki kedekatan dengan kelompok Streptomyces spp.


2020 ◽  
Vol 21 (21) ◽  
pp. 7912 ◽  
Author(s):  
Tatyana Odintsova ◽  
Larisa Shcherbakova ◽  
Marina Slezina ◽  
Tatyana Pasechnik ◽  
Bakhyt Kartabaeva ◽  
...  

Hevein-like antimicrobial peptides (AMPs) comprise a family of plant AMPs with antifungal activity, which harbor a chitin-binding site involved in interactions with chitin of fungal cell walls. However, the mode of action of hevein-like AMPs remains poorly understood. This work reports the structure–function relationship in WAMPs—hevein-like AMPs found in wheat (Triticum kiharae Dorof. et Migush.) and later in other Poaceae species. The effect of WAMP homologues differing at position 34 and the antifungal activity of peptide fragments derived from the central, N- and C-terminal regions of one of the WAMPs, namely WAMP-2, on spore germination of different plant pathogenic fungi were studied. Additionally, the ability of WAMP-2-derived peptides to potentiate the fungicidal effect of tebuconazole, one of the triazole fungicides, towards five cereal-damaging fungi was explored in vitro by co-application of WAMP-2 fragments with Folicur® EC 250 (25% tebuconazole). The antifungal activity of WAMP homologues and WAMP-2-derived peptides varied depending on the fungus, suggesting multiple modes of action for WAMPs against diverse pathogens. Folicur® combined with the WAMP-2 fragments inhibited the spore germination at a much greater level than the fungicide alone, and the type of interactions was either synergistic or additive, depending on the target fungus and concentration combinations of the compounds. The combinations, which resulted in synergism and drastically enhanced the sensitivity to tebuconazole, were revealed for all five fungi by a checkerboard assay. The ability to synergistically interact with a fungicide and exacerbate the sensitivity of plant pathogenic fungi to a commercial antifungal agent is a novel and previously uninvestigated property of hevein-like AMPs.


2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984679 ◽  
Author(s):  
Haiyu Luo ◽  
Zhen Qing ◽  
Yecheng Deng ◽  
Zhiyong Deng ◽  
Xia’an Tang ◽  
...  

Endophytic fungi, especially those found in medicinal plants, are widely studied as producers of secondary metabolites of biotechnological interest. In this study, on the basis of an activity-directed isolation method and spectroscopic analysis, two active polyketides, citrinin (1) and emodin (2), were isolated and identified from the fermentation of the endophytic fungus Penicillium citrinum DBR-9. This fungus was isolated from the root tubers of the traditional Chinese medicinal plant Stephania kwangsiensis. In vitro antifungal assay showed that the two polyketides displayed significant inhibition on hypha growth of tested plant pathogenic fungi with IC50 values ranging from 3.1 to 123.1 μg/mL and 3.0 to 141.0 μg/mL, respectively. In addition, the mechanism of the effects of emodin (2) on the pathogen revealed it could affect the colony morphology, destroy cell membrane integrity, and influence the protein synthesis of the tested fungal cell. This work is the first report of two polyketides-producing endophytic P. citrinum DBR-9 from the medicinal plant S. kwangsiensis. Our results present new opportunities to deeply understand the potential of these two polyketides as natural antifungal agents to control phytopathogens in agriculture.


Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 573
Author(s):  
Hosapura Shekhararaju Mahesha ◽  
Jayasuvarnapura Umapathi Vinay ◽  
Medikeripura Rekhyanaik Ravikumar ◽  
Suryanarayana Visweswarashastry ◽  
Manikyanahalli Chandrashekhara Keerthi ◽  
...  

Plant pathogenic fungi and bacteria are a significant threat to global commercial crop production resulting in increased cost of production, reduced crop establishment and productivity. An effort was made to study the antimicrobial activity of silver hydrogen peroxide (SHP) against selected plant pathogenic fungi and bacteria under in vitro conditions. Higher antibacterial activity of SHP was observed against Xanthomonas axonopodis pv. citri (Xac; 39.67 mm), Xanthomonas citri pv. punicae (Xap; 39.00 mm), and Ralstonia solanacearum (Rs; 36.67 mm) at 500 ppm concentration. SHP was superior to streptocycline (500 ppm) against Xac (25.33 mm) and Xcp (22.67 mm) at 100 ppm. The soil-borne fungi viz., Pythium aphanidermatum and Fusarium solani failed to initiate mycelium growth on PDA at the concentration of 5000 ppm and above. The average size of SHP particles was 462 nm in diameter, and 73.40% of particles had the size of 378 nm, which reflects the particles present in SHP solution in the form of colloids. The effective doses (100–5000 ppm) did not show any phytotoxicity symptoms in plants, while leaf necrosis was noticed at 10,000 ppm after four days of application. SHP (≤5000 ppm) can be used to effectively manage both fungal and bacterial plant pathogens by a single application. Further field studies need to be conducted for validation and commercial use of SHP.


2003 ◽  
Vol 56 ◽  
pp. 100-102 ◽  
Author(s):  
H.F. Neilson ◽  
T.M. Stewart

A LUCIDtrade; multiaccess computerbased key for identifying 175 genera of plant pathogenic fungi of temperate crops is described The key takes a pragmatic rather than a taxonomic approach to identification enabling a nonspecialist to key out many suspected plant pathogens based on microscopic examination of the fungal structures and plant disease symptoms Taxonomic jargon is kept to a minimum and images of morphological characteristics are used frequently Fact sheets on the diseases caused by common pathogens are also included in the programme The key is available in the public domain and should be useful to anyone with a microscope wishing to identify a common fungal disease


2021 ◽  
Vol 12 ◽  
Author(s):  
Larisa Shcherbakova ◽  
Oleg Mikityuk ◽  
Lenara Arslanova ◽  
Alexander Stakheev ◽  
Denis Erokhin ◽  
...  

Thymol, a secondary plant metabolite possessing antifungal and chemosensitizing activities, disrupts cell wall or membrane integrity and interferes with ergosterol biosynthesis. Thymol also functions as a redox-active compound inducing generation of reactive oxygen species and lipid peroxidation in fungal cells. Previously, we showed thymol significantly enhanced the in vitro growth inhibitory effect of difenoconazole against Bipolaris sorokiniana and Parastagonospora nodorum. More recently, we demonstrated a possibility to use thymol to overcome the resistance of a P. nodorum strain able to grow on difenoconazole-containing media. However, potential for thymol to serve as a chemosensitizing agent in seed or plant treatments, to provide an effective suppression of the above-mentioned plant pathogens by triazole fungicides applied in lowered dosages, had yet to be tested. In the work presented here, we showed combined treatments of naturally infected barley seeds with thymol and difenoconazole (Dividend® 030 FS) synergistically exacerbated the protective effect against common root rot agent, B. sorokiniana, and other fungi (Fusarium spp. and Alternaria spp.). Similarly, co-applied treatment of wheat seeds, artificially inoculated with Fusarium culmorum, resulted in equivalent reduction of disease incidence on barley seedlings as application of Dividend®, alone, at a ten-fold higher dosage. In foliar treatments of wheat seedlings, thymol combined with Folicur® 250 EC (a.i. tebuconazole) enhanced sensitivity of P. nodorum, a glume/leaf blotch pathogen, to the fungicide and provided a significant mitigation of disease severity on treated seedlings, compared to controls, without increasing Folicur® dosages. Folicur® co-applied with thymol was also significantly more effective against a strain of P. nodorum tolerant to Folicur® alone. No additional deoxynivalenol or zearalenone production was found when a toxigenic F. culmorum was cultured in a nutrient medium containing thymol at a concentration used for chemosensitization of root rot agents. Accordingly, F. culmorum exposure to thymol at the sensitizing concentration did not up-regulate key genes associated with the biosynthesis of trichothecene or polyketide mycotoxins in this pathogen. Further studies using field trials are necessary to determine if thymol-triazole co-applications result in sensitization of seed- and foliar-associated plant pathogenic fungi, and if thymol affects production of fusarial toxins under field conditions.


2021 ◽  
Vol 7 (3) ◽  
pp. 163 ◽  
Author(s):  
Sabelle Jallow ◽  
Nelesh P. Govender

Ibrexafungerp (formerly SCY-078 or MK-3118) is a first-in-class triterpenoid antifungal or “fungerp” that inhibits biosynthesis of β-(1,3)-D-glucan in the fungal cell wall, a mechanism of action similar to that of echinocandins. Distinguishing characteristics of ibrexafungerp include oral bioavailability, a favourable safety profile, few drug–drug interactions, good tissue penetration, increased activity at low pH and activity against multi-drug resistant isolates including C. auris and C. glabrata. In vitro data has demonstrated broad and potent activity against Candida and Aspergillus species. Importantly, ibrexafungerp also has potent activity against azole-resistant isolates, including biofilm-forming Candida spp., and echinocandin-resistant isolates. It also has activity against the asci form of Pneumocystis spp., and other pathogenic fungi including some non-Candida yeasts and non-Aspergillus moulds. In vivo data have shown IBX to be effective for treatment of candidiasis and aspergillosis. Ibrexafungerp is effective for the treatment of acute vulvovaginal candidiasis in completed phase 3 clinical trials.


Apidologie ◽  
2019 ◽  
Vol 50 (6) ◽  
pp. 871-880 ◽  
Author(s):  
Jorgiane B. Parish ◽  
Eileen S. Scott ◽  
Raymond Correll ◽  
Katja Hogendoorn

AbstractHoney bees, Apis mellifera, have been implicated as vectors of plant pathogens. However, the survival of spores of plant pathogenic fungi through the digestive tract of workers has not been investigated. As workers defecate outside the hive, transport of hives could give rise to biosecurity concerns if fungal spores remain viable following passage through the digestive tract. To determine the likelihood that honey bees serve as vectors, this study investigated the viability of spores of Botrytis cinerea and Colletotrichum acutatum after passing through the digestive tract of summer and autumn worker bees. For both fungi, the mean viability of spores in faeces suspensions was less than one percent of the initial dose fed to the bees. Although survival was low, the large number of workers per hive implies a high probability of transmission of viable spores through honey bee faeces. Hence, in the case of economically important fungal diseases, transported hives could be a source of inoculum and quarantine restrictions should be considered.


2014 ◽  
Vol 53 (4) ◽  
pp. 438-440
Author(s):  
Liliana Gallez ◽  
Mirta Kiehr ◽  
Leticia Fernández ◽  
Rolf Delhey ◽  
Débora Stikar

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1037-1043 ◽  
Author(s):  
Young-Ki Jo ◽  
Byung H. Kim ◽  
Geunhwa Jung

Silver in ionic or nanoparticle forms has a high antimicrobial activity and is therefore widely used for various sterilization purposes including materials of medical devices and water sanitization. There have been relatively few studies on the applicability of silver to control plant diseases. Various forms of silver ions and nanoparticles were tested in the current study to examine the antifungal activity on two plant-pathogenic fungi, Bipolaris sorokiniana and Magnaporthe grisea. In vitro petri dish assays indicated that silver ions and nanoparticles had a significant effect on the colony formation of these two pathogens. Effective concentrations of the silver compounds inhibiting colony formation by 50% (EC50) were higher for B. sorokiniana than for M. grisea. The inhibitory effect on colony formation significantly diminished after silver cations were neutralized with chloride ions. Growth chamber inoculation assays further confirmed that both ionic and nanoparticle silver significantly reduced these two fungal diseases on perennial ryegrass (Lolium perenne). Particularly, silver ions and nanoparticles effectively reduced disease severity with an application at 3 h before spore inoculation, but their efficacy significantly diminished when applied at 24 h after inoculation. The in vitro and in planta evaluations of silver indicated that both silver ions and nanoparticles influence colony formation of spores and disease progress of plant-pathogenic fungi. In planta efficacy of silver ions and nanoparticles is much greater with preventative application, which may promote the direct contact of silver with spores and germ tubes, and inhibit their viability.


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