PENGARUH PUPUK HAYATI DENGAN KOMPOSISI MIKROORGANISME YANG BERBEDA TERHADAP PERTUMBUHAN TANAMAN

Biofertilizer can be used to replace chemical fertilizer so that soil quality is maintained and soil pollution can be avoided. The study aimed to determine the effect of biofertilizers with different compositions of microorganisms on the growth of maize plants. The research was carried out in a greenhouse. Maize plants were fertilized by two kinds of biofertilizers with different compositions of microorganisms. The first biofertilizer contained Azotobacter sp, Azospirillum sp, Rhizobium sp, Trichoderma sp, and Lactobacillus sp, and the second biofertilizer contained Strenotrophomonas sp. and Paenibacillus polymyxa. As controls, maize plants were fertilized by sterilized those biofertilizers. The results showed that the second biofertilizer increased the dry weight of the maize plant. Meanwhile, the first biofertilizer did not increase it. Several things must be considered in the application of biofertilizers, such as the composition of microorganisms, type of plant, level of fertilization, and the method of applying fertilizer to the plant.

Biocontrol of Anthracnose Disease on Chili Pepper Using a Formulation Containing Paenibacillus polymyxa C1

Anthracnose disease on chili pepper has been known to seriously interfere with the plant growth and obviously reduce the yield. The disease is caused by Colletotrichum spp. In Bali, Indonesia, six species of Colletotrichum have been identified: Colletotrichum scovillei, C. acutatum, C. nymphaeae, C. gloeosporioides, C. truncatum, and C. fructicola. However, among them the C. scovillei was found to be the most prevalent cause of anthracnose on chili pepper in Bali. Two species of antagonist against C. scovillei, namely Paenibacillus polymyxa C1 and Bacillus siamensis C7B, have been identified. In this study the effectiveness of P. polymyxa C1 formulation was evaluated under greenhouse condition on chili pepper cultivars Cabe Besar. Application of formulation was conducted by a mini hand sprayer once to five times with a week interval. Results of the study showed that treatment with five applications significantly (p < 0.05) reduced the disease incidence, disease intensity, and the yield loss of chili pepper cultivar Cabe Besar. Alose relationship was observed between the number of applications with disease intensity, with coefficient of determination (R2) at 0.929. These results revealed that the formulation of P. polymyxa C1 effectively control the anthracnose disease on chili pepper, particularly on chili pepper cultivar Cabe Besar, and thus can be recommended for field testing to confirm its stability under field conditions.

Fusaricidin Biosynthesis Is Controlled via a KinB-Spo0A-AbrB Signal Pathway in Paenibacillus polymyxa WLY78

Fusaricidins produced by Paenibacillus polymyxa are important lipopeptide antibiotics against fungi. The fusGFEDCBA (fusaricidin biosynthesis) operon is responsible for synthesis of fusaricidins. However, the regulation mechanisms of fusaricidin biosynthesis remain to be fully clarified. In this study, we revealed that fusaricidin production is controlled by a complex regulatory network including KinB-Spo0A-AbrB. Evidence suggested that the regulator AbrB represses the transcription of the fus gene cluster by direct binding to the fus promoter, in which the sequences (5′-AATTTTAAAATAAATTTTGTGATTT-3′) located from −136 to −112 bp relative to the transcription start site is required for this repression. Spo0A binds to the abrB promoter that contains the Spo0A-binding sequences (5′-TGTCGAA-3′, 0A box) and in turn prevents the further transcription of abrB. The decreasing concentration of AbrB allows for the derepression of the fus promoter repressed by AbrB. The genome of P. polymyxa WLY78 contains two orthologs (named Kin1508 and Kin4833) of Bacillus subtilis KinB, but only Kin4833 activates sporulation and fusaricidin production, indicating that this kinase may be involved in phosphorylating Spo0A to initiate sporulation and regulate the abrB transcription. Our results reveal that Kin4833 (KinB), Spo0A, and AbrB are involved in regulation of fusaricidin production and a signaling mechanism that links fusaricidin production and sporulation. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Growth promotion of raspberry and strawberry plants by bacterial inoculants

Study on potential mechanisms influencing the growth of raspberry and strawberry plants showed that the most active was Bacillus sp. strain AF75BC producing IAA and siderophores, and having the ability to release phosphorus. The latter feature was also present in the strains Sp115AD (B. subtilis) and SP116AC (Paenibacillus polymyxa). Two of the tested strains: SP116AC and JaFGU (Lysobacter sp.) showed the ability to fix atmospheric nitrogen, while the AF75AB2 (Bacillus sp.) produced siderophores and IAA. All strains showed an antagonism toward the most important pathogens of strawberry and raspberry, i.e. Verticillium dahliae, Botrytis cinerea, Phytophthora cactorum and Colletotrichum acutatum, limiting their growth to a different extent on the PDA medium. Inoculation of raspberry roots with the tested bacteria resulted in an increase of some growth parameters of their above-ground part in cv. Poemat. In the case of cv. Polana, a significant increase was found only in the chlorophyll content in the leaves. All the inoculants caused an increase in dry mass of roots in cv. Polana, and in cv. Poemat similar effect was observed after applying Inoculants 1 and 3. The treatments of strawberry roots with any of the inoculants resulted in a significant increase in the total leaf surface area in cv. Rumba, but they had no effect on the chlorophyll content in the leaves of either cultivar. All the inoculants significantly increased the total length of roots and their total surface area in cv. Rumba. This parameter also increased in cv. Elsanta, and the number of root tips also significantly increased in this cultivar. Our study showed that the tested inocula is a promising alternative as a bio-fertilizer for small fruit production in sustainable and organic agricultural systems.

Antitoxin EndoAI can induce disease resistance in tobacco as a protein elicitor

Background The antitoxin EndoAI is a TA system component that directly inhibits EndoA activity in vitro. The targeted activation of a TA system represents a potentially novel antimicrobial or antiviral strategy. However, whether the antitoxin functions alone and can induce plant disease resistance remain unknown. Results An endoAI was previously identified in the genome of Paenibacillus terrae NK3-4. It underwent a bioinformatics analysis, cloned and expressed in Escherichia coli. Then the functions of EndoAI inducing plant resistance to diseases as an elicitor were evaluated. The results showed that, EndoAI is a stable, alkaline, and hydrophilic protein, with a J-shaped three-dimensional structure in the absence of a ligand. It was clustered on the same branch with an antitoxin from Paenibacillus polymyxa SC2. Ectopically expressed EndoAI triggered a reactive oxygen species burst and a positive hypersensitive response (HR) in tobacco leaves. Moreover, 2 μmol EndoAI induced HR activity in tomato leaf, and it remained active after a 15-min exposure at 4–50 °C, and pH 6–8. Additionally, EndoAI induced plant systemic resistance against Alternaria alternata and tobacco mosaic virus, and the up-regulated transcription of PR genes, including PR1a, PR1b, PR5, PDF1.2, COL1, NPR1, and PAL. Conclusions These results imply that EndoAI may enhance the disease resistance of tobacco by promoting a series of early defense responses and up-regulating PR gene expression. These findings are relevant for future investigations on the mechanism underlying the EndoAI–plant interaction that leads to enhanced disease resistance. Furthermore, the endoAI may be useful for developing effective biocontrol agents to protect plants from diseases. Graphical Abstract

Paenibacillus Polymyxa MVY-024: Plant Growth Promoting Bacteria Which is Easy to Apply on an Industrial Scale

In this study, thirteen isolates which were possibly expected to fix nitrogen, were isolated from the soil and pea root nodules and identified by gene analysis of 16S rDNA sequences. Two of these isolates which were able to form endospores and growth on nitrogen free media were selected for spring wheat development research. The isolate Paenibacillus sp. S7 identified as Paenibacillus polymyxa was found to significantly increased amount of ammonium and mineral N amounts in the soil. Furthermore, increased nitrogen accumulation in grain and a chlorophyll index were obtained after wheat treatment. Paenibacillus sp. S7 isolate was selected for further studies and accession number MT900581 and strain name MVY-024 in NCBI nucleotide bank for this isolate was assigned. During cultivation of Paenibacillus sp. MVY-024, sugarcane molasses and yeast extract were determined as the most suitable carbon and nitrogen sources, optimal concentrations were 100 gL-1 and 10 gL-1, respectively. The optimal pH range for cells culturing was between 6.5 and 7.0, optimal air flow rate was 0.4 vvm. It was found that air flow has effect for biomass production and cells endospores formation. After Paenibacillus sp. MVY-024 biomass cultivation optimization, cultured cells number was on average 2.2 × 109 cfu mL-1.

Fusaricidins, Polymyxins and Volatiles Produced by Paenibacillus polymyxa Strains DSM 32871 and M1

Paenibacilli are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in agrobiotechnology. Lipopeptides produced by such organisms play a major role in their potential to inactivate pathogens. In this work we investigated two lipopeptide complexes, the fusaricidins and the polymyxins, produced by Paenibacillus polymyxa strains DSM 32871 and M1 by MALDI-TOF mass spectrometry. The fusaricidins show potent antifungal activities and are distinguished by an unusual variability. For strain DSM 32871 we identified numerous yet unknown variants mass spectrometrically. DSM 32871 produces polymyxins of type E (colistins), while M1 forms polymyxins P. For both strains, novel but not yet completely characterized polymyxin species were detected, which possibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins have gained increasing attention as last-resort antibiotics against multiresistant pathogenic Gram-negative bacteria. In addition, the volatilomes of DSM 32781 and M1 were investigated with a GC–MS approach using different cultivation media. Production of volatile organic compounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an efficient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of Paenibacilli is the formation of volatile pyrazine derivatives.