Antagonistic activity of cellulase-producing yeasts isolated from cocoa fermentation against pathogenic molds collected from damaged cocoa fruits
Dalia Sukmawati1,2*, Alika Firhandini1, Umi Khumaiya1, D.A. Komsiatun1, Atin Supiyani1, Dwi Ningsih Susilowati3, Shabrina Nida Al Husna4, Hesham El Enshasy5,6, Daniel Joe Dailin5, and Catur Sriherwanto7

1Biology Department, Laboratory of microbiology, 9th Floor Hasyim Ashari Building, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia- Dalia-Sukmawati[at]unj.ac.id
2Universitas Negeri Jakarta Culture Collection, Laboratory of microbiology, 9th Floor Hasyim Ashari Building, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia- Dalia-Sukmawati[at]unj.ac.id-
1 Biology Department, Laboratory of microbiology, 9th Floor Hasyim Ashari Building, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia- allika.firhandini.bioa17[at]gmail.com
1Biology Department, Laboratory of microbiology, 9th Floor Hasyim Ashari Building, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia- umikhumaiya_1308617072[at]mhs.unj.ac.id
1Biology Department, Laboratory of microbiology, 9th Floor Hasyim Ashari Building, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia- atinsupiyani78[at]gmail.com
3Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian, Indonesia Jl. Tentara Pelajar No. 3A, Bogor 16111, Jawa Barat, Indonesia Telp. (0251) 8337975, 8354985- Faks. (0251) 8338820. Email: d_nengsusi[at]yahoo.com
4Department of Microbiology, School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, Jawa Barat, Indonesia- shabrina.nida[at]gmail.com
5Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia- henshasy[at]ibd.utm.my
5Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia- Email: jddaniel[at]utm.my
6City of Scientific Research and Technology Applications, New Burg Al Arab, Alexandria, Egypt- Email:henshasy[at]ibd.utm.my
7Centre for Applied Microbiology, National Research and Innovation Agency (BRIN), Science and Technology Park, Banten, Indonesia- Email: catur.sriherwanto[at]brin.go.id

Abstract

The presence of pathogenic molds in post-harvested cocoa beans poses a significant problem to most Indonesian farmers. Pathogenic molds secrete phytopathogenic toxins which cause rotting, seriously damaging the cocoa fruits. The common pathogenic molds found in damaged cocoa beans are Phytophthora palmivora and Phytophthora megakarya. These molds are so far controlled by using chemical pesticides, whose the long-term use is potentially harmful to human health and environment. Thus, healthier and safer alternative is needed, especially using biological agents such as yeasts. Some yeasts produce cellulose-degrading enzymes that can possibly break down the fungal cell wall which is composed mostly of the polysaccharides chitin and glucan. In this study, yeasts were isolated during the cocoa fermentation process, followed by screening for cellulolytic activity using direct planting and paste method, and subsequent antagonistic testing by double culture technique. Out of 128 yeast isolates, 77 possessed cellulase activity, with 6 of them having the highest activity index. Antagonistic activity test of these 6 isolates (C1.0.4, C1.1.3, C2.3.10, C2.3.14, C3.5.11, and C3.3.1) against the pathogenic molds resulted in isolate C3.3.1 showing the highest inhibition percentage from the 2nd to 8th day of incubation.

Keywords: Antagonistic activity, yeasts, cocoa fermentation, Phytophthora palmivora

Topic: Biology