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High-performance liquid chromatography (HPLC) analysis results showing degradation of a synthetic chitopentamer by the Cho protein of A. fertilissima.
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Two contrasting cyanobacterial species (Anabaena fertilissima and Anabaena sphaerica) were selected based on differences in antifungal behavior in order to study the mechanism for production of an antifungal
enzyme and the genes responsible for this production. In A. fertilissima, chitosanase and antifungal activities were increased significantly u...
Citations
... These hydrolases also assist in the digestion of the fungal cell wall [185]. In cyanobacteria, the occurrence of the homologs of chitosanases was initially reported in three strains of Anabaena: A. laxa RPAN8, Anabaena iyengarii RPAN9, and A. fertilissima RPAN1 [186,187]. Their production was positively correlated with the fungicidal properties observed in the supernatant of these microorganisms [186]. The chitosanase of A. fertilissima RPAN1 (Cho), in accordance with its catalytic site, is associated with the GH3-like family, and can degrade chitotetrose and longer chitosan oligosaccharides into dimers and trimers, but it does not significantly act on chitobiose and chitotriose. ...
... One plausible explanation for this correlation lies in the fact that the increase in the length of the light period affords a higher quantity of quantum available for photosynthesis; this results in a higher carbohydrate accumulation that can act as a carbon and energy source for the construction of fungicidal biomolecules [302]. These observations differ from those reported by Gupta and his research group [187] who detected a positive contribution during the dark period with regard to anti-fungal chitinase production from A. fertilissima RPAN1. Growth retardation and photosynthetic efficiency reduction were also observed in this strain when the light period was shortened, and the aforementioned effects are likely to be related to this event [187]. ...
... These observations differ from those reported by Gupta and his research group [187] who detected a positive contribution during the dark period with regard to anti-fungal chitinase production from A. fertilissima RPAN1. Growth retardation and photosynthetic efficiency reduction were also observed in this strain when the light period was shortened, and the aforementioned effects are likely to be related to this event [187]. Similarly, Ibraheem and coworkers found that the L: D-16:8 cycle favors the release of a higher quantity of bioactive compounds against C. albicans IMRU 3669, A. alternata, A. flavus IMI 111023, F. solani, and Pythium sp. from the cyanobacterium, C. minutus, as compared with the conditions of 24-L and 24-D [303]. ...
Cyanobacteria are a rich source of secondary metabolites, and they have received a great deal of attention due to their applicability in different industrial sectors. Some of these substances are known for their notorious ability to inhibit fungal growth. Such metabolites are very chemically and biologically diverse. They can belong to different chemical classes, including peptides, fatty acids, alkaloids, polyketides, and macrolides. Moreover, they can also target different cell components. Filamentous cyanobacteria have been the main source of these compounds. This review aims to identify the key features of these antifungal agents, as well as the sources from which they are obtained, their major targets, and the environmental factors involved when they are being produced. For the preparation of this work, a total of 642 documents dating from 1980 to 2022 were consulted, including patents, original research, review articles, and theses.
... Culture filtrates of Anabaena laxa and N. muscorum reduced the oomycete P. aphanidermatum and the fungus Penicillium sp. growth, respectively [99,105]. The growth of a different species of Penicillium, P. verrucosum, was also reduced by a diethyl ether extract from Microcystis aeruginosa that belongs to Chroococcales order [97]. ...
... The antifungal activity shown in Table 1 is mainly referred to cyanobacteria extracellular culture filtrates [17,21,22,105] and to extracts obtained from cyanobacteria with different organic solvents, such as acetone, chloroform, diethyl ether, ethyl acetate, ethanol, methanol, methyl chloride, n-propanol, petroleum and petroleum ether [17,21,22,[97][98][99][100][101][102][103][104][105][106], as well as water [100]. The culture filtrates are rich of many substances that can display interesting antifungal activity. ...
... The antifungal activity shown in Table 1 is mainly referred to cyanobacteria extracellular culture filtrates [17,21,22,105] and to extracts obtained from cyanobacteria with different organic solvents, such as acetone, chloroform, diethyl ether, ethyl acetate, ethanol, methanol, methyl chloride, n-propanol, petroleum and petroleum ether [17,21,22,[97][98][99][100][101][102][103][104][105][106], as well as water [100]. The culture filtrates are rich of many substances that can display interesting antifungal activity. ...
Cyanobacteria, also called blue-green algae, are a group of prokaryotic microorganisms largely distributed in both terrestrial and aquatic environments. They produce a wide range of bioactive compounds that are mostly used in cosmetics, animal feed and human food, nutraceutical and pharmaceutical industries, and the production of biofuels. Nowadays, the research concerning the use of cyanobacteria in agriculture has pointed out their potential as biofertilizers and as a source of bioactive compounds, such as phycobiliproteins, for plant pathogen control and as inducers of plant systemic resistance. The use of alternative products in place of synthetic ones for plant disease control is also encouraged by European Directive 2009/128/EC. The present up-to-date review gives an overall view of the recent results on the use of cyanobacteria for both their bioprotective effect against fungal and oomycete phytopathogens and their plant biostimulant properties. We highlight the need for considering several factors for a proper and sustainable management of agricultural crops, ranging from the mechanisms by which cyanobacteria reduce plant diseases and modulate plant resistance to the enhancement of plant growth.
... Based on previous work, it is known that several strains of Anabaena and Calothrix exerted activity against species of Pythium, Fusarium and Rhizoctonia (Prasanna et al., 2008;Manjunath et al., 2010). Among all the compounds synthetized by cyanobacteria, chitosanase homologues, endoglucanase and benzoic acid were detected, and their presence was correlated to the activity against phytopathogenic fungi and oomycetes (Gupta et al., 2010(Gupta et al., , 2011Prasanna et al., 2010). Chitosanase enzymes selectively decompose chitosan and chitin by hydrolysis of the β-(1, 4)-glycosidic bonds that link N-acetyl glucosamine residues of chitin. ...
This work highlights the ability of various cyanobacterial extracts from Anabaena spp., Tolypothrix spp., Nostoc or Trichormus, among others genera, to control the incidence of damping-off caused by Pythium ultimum in cucumber seedlings. Protocols applied aimed at the preliminary characterization of the cyanobacterial collection were very useful for predicting their phytotoxic, phytostimulating and biopesticidal capacity. First, the phytostimulatory or phytotoxic potential of a collection of 31 sonicated cyanobacterial extracts was analyzed by calculating the germination index in watercress seeds and the increase or loss of seedling weight. Likewise, the collection was characterized according to its ability to inhibit the growth of P. ultimum by dual culture bioassays and detached-leaf test. Finally, after selecting the most effective extracts, a preventive damping-off bioassay was performed based on cucumber seed biopriming. The strain SAB-M465 showed to be the most efficient strain against the in vitro growth of P. ultimum, while SAB-B912 was more discreet in this regard, but proved to be the most effective as a germination stimulator. Seed biopriming strategy with sonicated extracts of cyanobacteria revealed a remarkable promoter effect in the early stages of plant development, although only SAB-M465 was positioned as an effective control agent against damping-off caused by P. ultimum in cucumber seedbeds.
... Chitosanases in GH family 3 display anti-fungal chitosanase activity (Gupta et al., 2010), but are rare among the other members of the GH3 family which also includes -). Chitosanase activity observed in GH family 5 has been described as a "side activity" for only a small number of enzymes which are primarily cellulase enzymes (Aam et al., 2010). ...
The Irish mushroom production industry continues to grow rapidly. The two main waste streams from this are spent mushroom substrate (SMS) and mushroom stalks. This study focuses on identifying and the recombinant production of novel thermostable glycoside hydrolase enzymes with potential application in the valorisation of these waste streams. Two GH10 xylanases and three GH18 chitinases were expressed in P. pastoris. One xylanase (Xyn1) comprises of only a GH10 catalytic domain, the other (Xyn12) contains a GH10 catalytic domain and a CBM1 domain at the C’ terminus. The chitinases comprise of a GH18 catalytic domain only (Chit1), a GH18 catalytic domain and a ChitBM domain (Chit 2), and a GH18 catalytic domain and a substrate insertion domain (Chit3). The enzymes originate from the genome of the thermophilic filamentous fungus R. emersonii, which is known to produce thermostable commercially interesting enzymes.
The xylanases display low pH (4-4.5) and high temperature (70-80°C) optima. They are thermostable, with over 50% relative activity remaining after 48h incubation at 65°C. To further understand the role of the CBM1, both enzymes underwent protein engineering whereby the CBM1 and linker region were removed from Xyn12, and added to the C’terminus of Xyn1. This affected the stability of the enzymes; the removal saw a drop in relative activity from 84% to 46% and the addition increased the thermostability from 65% to over 90% after 48h incubation at 65°C.
All chitinases displayed endo-chitinase and chitobiosidase activity. Chit3 also displayed some N-acetyl-glucosamidase activity, likely due to the substrate insertion domain causing catalytic-cleft deepening. The chitinases displayed temperature optima of 50 – 55 °C, and low pH optima (pH 4.5 or lower). In particular, Chit3 indicated a pH optimum of pH 2.8. As far as we are aware, this is the lowest pH optima of a fungal chitinase to date. Chit2 displayed the highest chitin-degrading ability at 3456 µmol/mg/mL on 4-NP -triacetylchitotriose, with Chit1 displaying 403 µmol/mg/mL, and Chit3 displaying 268 µmol/mg/mL (on 4-NP-chitobioside). The chitinases displayed thermostability; Chit1 was markedly thermostable with over 70% relative activity remaining after 48h incubation at 50 °C. Chit2 displayed the lowest thermostability with 14 % remaining after 48h incubation at 50 °C.
During preliminary industrial testing, Xyn1 yielded a notable reduction in viscosity of WE-SAX of 79.3% in 15 mins in comparison to controls. Xyn1 produced short-chain xylooligosaccharides from the same substrate. Chit1 and Chit3 displayed efficacy in hydrolysing shrimp and fungal chitin. These features, coupled with the thermostability of the enzymes, indicate suitability of Xyn1 for application in wheat-starch processing and animal feed, and suitability of the chitinases in valorisation of waste streams of industrial shrimp and mushroom production, and in the healthcare industry namely in the production of glucosamine supplements and designed human milk oligosaccharides.
... PPO (Polyphenol oxidase) (EC, 1.14.18.1) and PO (Peroxidase) (EC, 1.11.1.x) in Anabaena and Calothrix strains showed a significant correlation with fungicidal activity (Gupta et al. 2010; Natarajan et al. 2013; Prasanna et al. 2008). The significant role of cyanobacteria in disease reduction and defense against fungal diseases of vegetables is evidenced through the increase in the number of publications in this area in the last decade (Manjunath et al. 2010; Dukare et al. 2011; Gupta et al. 2010 Gupta et al. , 2011 Gupta et al. , 2013 Prasanna et al. 2008 Prasanna et al. , 2014 Prasanna et al. , 2015 ). ...
... in Anabaena and Calothrix strains showed a significant correlation with fungicidal activity (Gupta et al. 2010; Natarajan et al. 2013; Prasanna et al. 2008). The significant role of cyanobacteria in disease reduction and defense against fungal diseases of vegetables is evidenced through the increase in the number of publications in this area in the last decade (Manjunath et al. 2010; Dukare et al. 2011; Gupta et al. 2010 Gupta et al. , 2011 Gupta et al. , 2013 Prasanna et al. 2008 Prasanna et al. , 2014 Prasanna et al. , 2015 ). Cyanobacteria are also capable of proliferation as biofilms in aquatic and soil environments, mainly mediated through their metabolic plasticity and production of polysaccharide sheath or mucilage (Prasanna et al. 2013a, b). ...
... Our earlier studies had shown that such endoglucanases are present in cyanobacteria used in this study and are also known in Trichoderma spp. (Gupta et al. 2010Gupta et al. , 2011Gupta et al. , 2013 Natarajan et al. 2012 Natarajan et al. , 2013). In the present study, microscopic analyses of root tissues revealed the presence of the inoculated strains, including cyanobacteria. ...
The performance of cyanobacteria and Trichoderma based biocontrol formulations was evaluated in two cotton varieties (Gossypium hirsutum F1861 and Gossypium arboreum CISA 310). Evaluation of mortality after 4 weeks revealed a significant reduction, particularly in G. hirsutum F1861, with values of 13 % (lower by 2 % over the Trichoderma commercial biocontrol agent). The percent mortality after drenching with the compost tea prepared using respective formulations, ranged from 28 to 75 % in G. arboreum CISA 310, with significantly lower values of 6–37.3 % in G. hirsutum. The Anabaena laxa RPAN8 formulation showed the lowest mortality. The activity of hydrolytic enzymes—β-1, 3 glucanase (EGase EC 3.2.1.39), β-1, 4 glucanase (EGase EC, 3.2.1.4) and chitosanase (EC 3.2.1.99) showed a significant enhancement in the inoculated treatments (T1–T6), with Calothrix sp. being among the top ranked treatments in both varieties. Comparison of DNA fingerprints (HIP-TG profiles) of rhizospheric soil DNA with those of corresponding pure cultures revealed a high degree of similarity, confirming the colonization of inoculated organisms. An amplicon of 1000 bp was observed in the soil metagenomic PCR-DNA profiles from both varieties, which confirmed the presence of an endoglucanase gene. Comparative analyses of responses of the two varieties revealed that Gossypium hirsutum F1861 showed higher values of hydrolytic enzymes and available N in soil. On the other hand, microbial inoculation elicited higher levels of chitosanase and defense enzyme activity in Gossypium arboreum CISA 310. This represents a first report illustrating the significance of varietal responses in cotton in relation to the efficacy of microbial biocontrol formulations and their establishment in the rhizosphere.
... At Sirsa, the microbiological and plantrelated assays revealed significant interactions of inoculated organisms and plant in sick plots, leading to lower or comparable levels of mortality as observed with commercial chemical or biocontrol formulations. Our earlier studies have shown that Anabaena, Calothrix sp. and biofilmed formulations exhibit fungicidal activity, which could be correlated with the production of hydrolytic enzymes, and homologues for chitosanase/endoglucanase were identified in these strains (Gupta et al., 2010Gupta et al., , 2012 Natarajan et al., 2012; Prasanna et al., 2008 Prasanna et al., , 2010 Prasanna et al., , 2011 Prasanna et al., , 2013b). Synergy among partners in the biofilmed formulations illustrated the potential of Anabaena as a matrix which can prove to be more viable inoculation option for organic agriculture practices (Prasanna et al., 2013a, c). ...
The potential of cyanobacteria-based compost formulations was evaluated in cotton crop at two agro-ecological locations (Nagpur and Sirsa) as plant growth promoting (PGP) and biocontrol agents. Compost-based formulations fortified with Calothrix sp. or Anabaena sp. enhanced germination and fresh weight of plants, and microbiological activity by 10-15%, besides increased available nitrogen (by 20-50%) in soil at Nagpur. In the fungi-infected fields at Sirsa, Anabaena-T. viride biofilmed formulation performed the best, recording 11.1% lower plant mortality than commercial Trichoderma formulation. Scanning electron microscopy confirmed the colonisation of inoculated cyanobacteria/biofilms on roots. Significant correlation between mortality, increased activity of hydrolytic enzymes and fresh weight of plant roots were recorded. Calothrix sp. and Anabaena sp. proved promising as both PGP and biocontrol agents, while biofilmed formulations substantially reduced mortality of cotton plants in sick plots. This study illustrates the promise of cyanobacteria as viable inoculation option for integrated nutrient and pest management strategies of cotton.
... Prasanna et al. (2008) for the first time revealed the activity of hydrolytic enzymes in several Anabaena strains and their correlation with antifungal activity. Chitosanase homologues and microcystin-like compounds were identified in two promising strains, Anabaena laxa and Anabaena Iyengarii, which exhibit fungicidal activity (Prasanna et al. 2010a; Gupta et al. 2010, 2011, 2012), and a novel antifungal chitosanase (cho) gene belonging to glycoside hydrolase family-3 from Anabaena fertilissima was characterized (Gupta et al. 2010). Antifungal b- 1,4-endoglucanases end and end 1 encoded by Calothrix elenkinii (Natarajan et al. 2012) and Anabaena sp. ...
... Prasanna et al. (2008) for the first time revealed the activity of hydrolytic enzymes in several Anabaena strains and their correlation with antifungal activity. Chitosanase homologues and microcystin-like compounds were identified in two promising strains, Anabaena laxa and Anabaena Iyengarii, which exhibit fungicidal activity (Prasanna et al. 2010a; Gupta et al. 2010, 2011, 2012), and a novel antifungal chitosanase (cho) gene belonging to glycoside hydrolase family-3 from Anabaena fertilissima was characterized (Gupta et al. 2010). Antifungal b- 1,4-endoglucanases end and end 1 encoded by Calothrix elenkinii (Natarajan et al. 2012) and Anabaena sp. ...
An investigation was done using cyanobacterium Anabaena torulosa as a matrix for developing novel biofilms, with anti-grazer traits against microfauna/pathogenic fungi, through co-inoculation of agriculturally important bacteria and fungi. The biofilms generated were evaluated after 4, 6 and 9 weeks of incubation for the activity of hydrolytic enzymes and fungicidal activity against phytopathogenic fungi. The activity of b-1,3-glucanase, in general, showed a gradual increasing trend up to 9 weeks, while endoglucanase activity was highest after 6 weeks of incubation, and a 40–50% reduction in chitosanase activity was recorded by the end of 9 weeks of incubation. Observations revealed that the fungus–cyanobacterium biofilms, especially Anabaena–Aspergillus awamori, exhibited the highest activity of b-1,3-glucanase and ranked second in terms of chitosanase activity. Fungicidal activity was recorded up to 9 weeks in most of the biofilms, and the highest values were recorded in cyanobacterium–Bacillus and cyanobacterium–fungus biofilms. Such biofilms were also tested against selected nematodes in microcosm experiments, which revealed no significant deleterious effects. The biocontrol activity of such biofilmed preparations against phytopathogenic fungi, but not towards selected nematodes, illustrates their promise in agriculture as potential inoculants that can effectively establish in soil.
... The cyanobacterial strains were axenized by standard procedures, employing a set of antibiotics (Kaushik 1987 ) and grown and maintained in nitrogen free BG- 11 medium, pH 7.5 (Stanier et al. 1971), under 28±1 ° C L: D (Light: Dark cycles 16:18), white light (50– 55 μmol photons m −2 s −1 ). The environmental conditions such as light, temperature, phosphorus and pH were previously optimized individually (continuous light, 38±1 °C temperature, phosphorus 344 μM twice the amount as present in BG11 medium and pH 9.5) in the tested cyanobacterial strains (Gupta et al. 2010Gupta et al. , 2011 Chaudhary et al. 2012a, b ), for maximizing production of hydrolytic enzymes and enhanced fungicidal activity. The fungal strain was grown and maintained on potato dextrose agar medium (CAB 1968), at 28±2 °C in a BOD incubator. ...
... The potential of PGPRs as biocontrol agents (BCAs) against soil borne plant pathogens of many important crops makes their application an attractive strategy within a sustainable agriculture framework (Compant et al. 2005; Sergeeva et al. 2002; Hofte and Altier 2010). Our first reports on the activity of hydrolytic enzymes such as chitosanases, xylanases, FPase in a set of Anabaena strains (Gupta et al. 2010Gupta et al. , 2011 Prasanna et al. 2008a, b) and their positive correlation with fungicidal activity, expanded the significant role of cyanobacteria, beyond nitrogen fixation or phytohormone-mediated plant growth promotion (Nayak et al. 2004; Prasanna et al. 2008a Prasanna et al. , 2009a). Cyanobacterial inoculation has been shown to enhance growth, root associated nitrogen fixation and yields of rice (Mandal et al. 1999; Nayak et al. 2004; Table 2 Percent increase over control in defence and pathogenesis related enzymes activities in roots of 14 days old tomato seedlings treated with different treatments under green house application Roger et al. 1993). ...
... Our earlier studies have shown that Anabaena and Calothrix sp. exhibit fungicidal activity, which could be correlated with the production of hydrolytic enzymes and the homologues for chitosanase/endoglucanase and benzoic acid were identified in these strains (Gupta et al. 2010Gupta et al. , 2011 Natarajan et al. 2012; Prasanna et al. 2008a, b; 2010a ). Radhakrishnan et al. (2009 recorded algicidal and fungicidal activity of culture filtrates of two cyanobacterial strains Calothrix elenkinii and Anabaena sp. ...
Cyanobacteria - phytopathogenic fungi - tomato plant interactions were evaluated for developing suitable biological options for combating biotic stress (Fusarium wilt) and enhancing plant vigour. Preliminary evaluation was undertaken on the fungicidal and hydrolytic enzyme activity of the cyanobacterial strains (Anabaena variabilis RPAN59, A. laxa RPAN8) under optimized environmental/nutritional conditions, followed by amendment in compost-vermiculite. Such formulations were tested against Fusarium wilt challenged tomato plants, and the Anabaena spp. (RPAN59/8) amended composts significantly reduced mortality in fungi challenged treatments, besides fungal load in soil. Cyanobacteria amended composts also led to an enhancement in soil organic C, nitrogen fixation, besides significant improvement in growth, yield, fruit quality parameters, N, P and Zn content. The tripartite interactions also enhanced the activity of defence and pathogenesis related enzymes in tomato plants. A positive correlation (r = 0.729 to 0.828) between P content and pathogenesis/defense enzyme activity revealed their role in enhancing the resistance of the plant through improved nutrient uptake. Light and scanning electron microscopy (SEM) revealed cyanobacterial colonization, which positively correlated with reduced fungal populations. The reduced disease severity coupled with improved plant growth/ yields, elicited by cyanobacterial treatments, illustrated the utility of such novel formulations in integrated pest and nutrient management strategies for Fusarium wilt challenged tomato crop.
... Chitosanase homologues and microcystin like compounds were identified in two promising strains—A. laxa and A. iyengarii which exhibit fungicidal activity [216] and a novel endo-type antifungal chitosanase (cho) gene belonging to glycoside hydrolase family-3 (GH3) from A. fertilissima was characterized [217,218] . The chitosanase and antifungal activities were found to increase significantly under conditions of growth limitation (L: D-8:16), as against L: D-16:8, and at stationary phase (28 d). ...
Cyanobacteria (blue-green algae) are Gram-negative oxygenic photosynthetic prokaryotes with a long evolutionary history. They have potential applications in diverse areas, especially in agriculture, as nutrient supplements in agriculture and industry (as biofertilizer, plant growth promoting rhizobacteria and as biocontrol agents). Their role as food supplements/nutraceuticals and in bioremediation and wastewater treatment is an emerging area of interest. In addition, they are known to produce wide array of bioactive compounds (secondary metabolites) with diverse biological activities — including antiviral, antibacterial, antifungal, antimalarial, antitumoral and anti-inflammatory properties, having therapeutic, industrial and agricultural significance. One of the major problems has been regarding their classification being incongruent with the phylogeny, because the phenotype of cyanobacterial strains is known to be altered under different environmental/nutritional conditions. However, because of their simple growth needs, they are the favourite model organisms for deeper understanding of several metabolic processes and for the production of recombinant compounds of medicinal and commercial value. In recent years, cyanobacteria have gained interest for producing third generation biofuels (both biomass and H2 production). With the recent advances in metabolic engineering techniques and availability of genome sequences, novel approaches are being explored for realising the potential of cyanobacteria. Our review provides an overview of the polyphasic approaches used in the analyses of cyanobacterial biodiversity and the potential of these organisms in providing viable solutions to global problems of food, energy and environmental degradation, which need further impetus through adoption of multidisciplinary collaborative programs.
... Among cyanobacteria, Nostoc muscorum is known to be effective against ''damping off'' disease caused by fungi (de Caire et al. 1990 ) and several Anabaena and Calothrix strains exhibit fungicidal activity against species of Pythium, Fusarium and Rhizoctonia (Moon et al. 1992; Prasanna et al. 2008; Radhakrishnan et al. 2009; Manjunath et al. 2010). Our earlier studies have shown that several cyanobacteria—including Calothrix sp. and Anabaena strains exhibit fungicidal activity which could be correlated with the production of hydrolytic enzymes and the homologues for chitosanase and endoglucanase have been detected in several Anabaena strains (Prasanna et al. 2008; Prasanna et al. 2010a; Gupta et al. 2010 Gupta et al. , 2011). The production of hydrolytic enzymes and their role in biocontrol has been reported earlier for bacterial strains (Singh et al. 1999; Grover et al. 2009; Dukare et al. 2011). ...
Biological control of plant pathogens is receiving increasing relevance, as compared to chemical methods, as they are eco-friendly, economical and indirectly improve plant quality and yield attributes. An investigation was undertaken to evaluate the potential of antagonistic cyanobacteria (Anabaena variabilis RPAN59 and A. oscillarioides RPAN69) fortified formulations for suppressing damping off disease in tomato seedlings challenged by the inoculation of a fungal consortium (Pythium debaryanum, Fusarium oxysporum lycopersici, Fusarium moniliforme and Rhizoctonia solani). Treatment with A. variabilis amended formulations recorded significantly higher plant growth parameters, than other treatments, including biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim). The A. variabilis amended compost-vermiculite and compost formulations exhibited 10-15 % lower disease severity and 40-50 % higher values than chemical and biological control treatments in terms of fresh weight and height of the plants. In future, in depth analyses regarding the mechanism involved in biocontrol by cyanobacteria and evaluation of these formulations under field conditions are proposed to be undertaken.
