Fungicide Activity of Culture Extract from Kocuria palustris 19C38A1 against Fusarium oxysporum.

Andi Setiawan,John Hendri,Masayoshi Arai,Wawan A Setiawan,Widyastuti Widyastuti,Mulyono Mulyono,Fernandy M Djailani,Fendi Setiawan,Aspita Laila,Ni Luh Gede Ratna Juliasih

doi:10.3390/jof8030280

Abstract

Secondary metabolites of actinomycetes are a potential source of bioactive compounds in the agricultural sector. This study aimed to determine the fungicidal properties of extracts of marine organism-derived actinomycetes. Actinomycetes were isolated from marine organisms using agar media with 1% colloidal chitin in artificial seawater. Then, the isolates were cultured on liquid media with 1% colloidal chitin in artificial seawater under static conditions for 14 days. The culture was extracted, the fungicide properties were evaluated using the microtiter 96-well plate method, and the influence of inhibition was visualized using apotome and SEM. Finally, the active extract was analyzed using LCMSMS. In the present study, 19 actinomycetes were isolated from marine organisms, and the isolates were examined with regard to their antifungal activities. Of these nineteen isolates, the isolate 19C38A1 was picked out from the rest. Hence, it showed significant control towards F. oxysporum. The prospective strain 19C38A1 was determined to be Kocuria palustris 19C38A1. The extract 19C38A1 was shown to cause damage to cell integrity, indicated by the shrinking form, and inhibited germination in the F. oxysporum; subsequently, the chemical characteristics of the compound produced by the potential isolate 19C38A1 indicated the presence of benzimidazole compounds in the active fraction of C38BK2FA. These results indicate that actinomycetes derived from marine organisms near the coast of Oluhuta, Tomini Bay, Gorontalo, related to strain 19C38A1, are not widely known as sources of valuable fungicides. This preliminary information is important, as it can be used as a basis for further development in the search for fungicides derived from marine actinomycetes.

Highlights

Chitin was transformed into colloidal chitin by concentrated HCl being added and it being stirred for 2 h; it was neutralized with distilled water to a pH of 7 and stored in a freezer at −20 ◦ C until it was used in further experiments [12]
Actinomycetes were isolated from 17 marine organisms collected from near the coast of Oluhuta, Tomini Bay, Gorontalo, Indonesia (0◦ 250 11.900 N 123◦ 080 31.800 E)
Samples of marine organisms were collected via Self-Contained Underwater Breathing Apparatus (SCUBA) diving at depths of 5–20 m

Summary

Introduction

Losses of agricultural products are generally caused by crop diseases, most of which are caused by soil-borne fungi, Fusarium oxysporum. This fungus is the main cause of the decline in the productivity of agricultural commodities such as bananas and cereal-based crops [1]. This is because plants are damaged by this fungus, and in addition, the rate of the spread of the fungus is relatively high [2]. Synthetic fungicides are still used to overcome this obstacle. The application of pesticides increased by 3.5 million tons by

Objectives

Methods

Results

Conclusion