Potential of an endophytic bacteria Bacillus amyloliquefaciens 3–5 as biocontrol agent against potato scab

Isolation was attempted to collect endophytic bacteria as potential biocontrol agents against rice blast disease (Pyricularia oryzae Cav.). The disease is one of major threats in rice production as it can cause 100% yield loss. Concern on the environment and human health has led to the searching of alternative controlling method to replace the commonly used pesticide-based method. Endophytic bacteria are bacteria that have intimate relationship with their host without inducing any pathogenic symptom. The use of endophytic microbial as biocontrol agent has its own advantages as the microbes are more easily to adapt to the environment needed by the host plant. We evaluated endophytic bacteria isolated from healthy rice plants and tested for their potential biocontrol activity using dual culture assay. Ten isolates were found to inhibit the growth of P. oryzae of more than 50%. Microscopic observation showed that they were able to cause the mycelia malformation of P. oryzae. Further work is currently in progress to determine their effectiveness in the pot trial. Keywords: Endophytic bacteria; Pyricularia oryzae; biocontrol.

Download Full-text

The ability of indigenous Bacillus spp. consortia to control the anthracnose disease (Colletrotricum capsici) and increase the growth of chili plants

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210123 ◽

2019 ◽

Vol 21 (1) ◽

Author(s):

Yulmira Yanti ◽

HASMIANDY HAMID ◽

REFLIN ◽

WARNITA ◽

TRIMURTI HABAZAR

Keyword(s):

Endophytic Bacteria ◽

Biocontrol Agent ◽

Alternative Control ◽

Anthracnose Disease ◽

Randomized Design ◽

Bacillus Spp ◽

Three Stages ◽

Completely Randomized Design ◽

Bacillus Toyonensis

Abstract. Yanti Y, Hamid H, Reflin, Warnita, Habazar T. 2019. The ability of indigenous Bacillus spp. consortia to control the anthracnose disease (Colletrotricum capsici) and increase the growth of chili. Biodiversitas 21: 179-186. Anthracnose disease caused by Colletotrichum capsici can reduce yields of chili up to 80%. The control of anthracnose disease is generally carried out using synthetic fungicides. However, the use of these fungicides can pollute the environment and harm human health. One alternative control that needs to be developed is the use of Bacillus spp. as a biocontrol agent. The study was conducted to obtain an indigenous Bacillus spp. consortium that compatible as a biological agent for the control of the anthracnose diseases and promoting the growth of chili plants. The experiment was arranged as a completely randomized design, consisted of three stages, namely: 1) inhibitory test of indigenous Bacillus spp. against C. capsici in vitro, 2) compatibility test of indigenous Bacillus spp. and 3) Test of indigenous Bacillus spp.consortium for controlling C. capsici and promoting the growth of chili. The results showed that eight species of indigenous endophytic bacteria could inhibit the growth of C. capsici in vitro. All combinations of indigenous Bacillus spp. were compatible for controlling C. capsici. Four combinations of Bacillus spp. were able to increase the growth of chili plants. K1 consortium (Bacillus pseudomycoides strain SLBE 3.1 AP, Bacillus thuringiensis strain SLBE 2.3 BB, Bacillus toyonensis strain AGBE 2.1 TL) was the best consortium for controlling C. capsici.

Download Full-text

A Strain of Bacillus amyloliquefaciens Can Prevent Vibrio vulnificus Colonization in Crassostrea gigas Oysters

Frontiers in Marine Science ◽

10.3389/fmars.2020.596343 ◽

2020 ◽

Vol 7 ◽

Author(s):

Andrea Martha Freire-Peñaherrera ◽

Ana Tirapé ◽

Jerry Landívar-Zambrano ◽

Juan Manuel Cevallos-Cevallos

Keyword(s):

Crassostrea Gigas ◽

Bacillus Amyloliquefaciens ◽

Biocontrol Agent ◽

Vibrio Vulnificus ◽

Biocontrol Agents ◽

Biocontrol Efficacy ◽

Solid Media ◽

Clinical Cases

The pathogen Vibrio vulnificus has been associated with the majority of clinical cases of septicemia and deaths attributed to shellfish consumption. However, reports on biocontrol agents against this pathogen are scarce. In this study, the strain A5 of Bacillus amyloliquefaciens (A5) was evaluated against V. vulnificus. The sensitivity of V. vulnificus to A5 was first assessed in vitro using selected solid media as well as autoclaved oysters (Crassostrea gigas). Then, the ability of A5 to colonize live oysters was evaluated, and the biocontrol efficacy was investigated in vivo using oysters inoculated with V. vulnificus before or after inoculation with A5. The survival of the pathogen in oysters was evaluated after 2, 3, 4, and 6 days of exposure to A5 in all the experiments. In vitro, A5 showed inhibition halos of 18 mm against V. vulnificus. In autoclaved oysters, A5 caused a significant reduction in the levels of V. vulnificus on day 2 at 5.14 log CFU/g, but the pathogen’s counts were restored after day 3. In vivo, A5 was able to survive in live oysters and prevented the colonization of V. vulnificus only when the biocontrol agent was inoculated before the pathogen. Results show the potential of A5 to prevent V. vulnificus uptake by oysters when administered prior to the pathogen.

Download Full-text