103 Lambuk et al. | Malaysian Journal of Fundamental and Applied Sciences, Vol. 19 (2023) 103-115 RESEARCH ARTICLE Isolation and Characterisation of Bacteria and Fungus from the Intestine of Sea Cucumber Acaudina molpadioides Fatmawati Lambuk a , Nurzafirah Mazlan b,* , Thung Tze Young c , Siti Marwanis Anua d , Ruzaina Ishak e a Faculty of Health and Life Sciences, Management and Science University, University Drive, Off Persiaran Olahraga, Seksyen 13, 40100 Shah Alam, Selangor, Malaysia; b Borneo Marine Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia; c Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Australia; d School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; e School of Health and Life Sciences, Teeside University, Middlesbrough, Tees Valley, TS1 3 BX, UK Abstract Acaudina molpadioides or locally known as ‘beronok’ is a high valued sea cucumber that is widely distributed in the muddy shores in the west coast Peninsular Malaysia and being consumed by the local people as traditional healthy delicacies. They are made into dishes and are usually consumed raw as ‘kerabu’. The aim of this study was to isolate and characterise the bacteria and fungus from the intestine of A. molpadioides using standard method for biochemical tests, safety assessments and molecular identification. A total of 100 samples were collected randomly from Pulau Langkawi, Malaysia and 1642 isolates were obtained from the intestine. Biochemical tests, safety evaluation and molecular identification were performed. Six strains (AM8h, AM47e, AM59a, AM67d, AM80d, and AM84d1) were selected for characterisation as they showed distinct morphology and from the biochemical tests. Further molecular identification showed the strains were identified as Priestia megaterium, Carnobacterium maltaromaticum, Bacillus tropicus, Staphylococcus saprophyticus, Bacillus cereus, and Yarrowia lipolytica (GenBank accession number: MZ947169, MZ934727, MZ947170, MZ934728, MZ934726, and MZ956769). The results indicated that both bacteria and fungus were presence in the intestine of A. molpadioides, hence there is a need for adequate measures in consuming this sea cucumber raw. Keywords: Acaudina molpadioides, antimicrobial activity, bacteria, fungi, sea cucumber. Introduction Sea cucumbers have been used traditionally as tonic food and medicinal resource in China, Japan, Korea, and south eastern Asian countries [1]. Acaudina molpadioides, known as sea potato or ‘beronok’ is a species of sea cucumber of order Molpadida and family Caudinidae [2]. This species inhabits in mud and it is a common species in the muddy shores in the west coast Peninsular Malaysia [3]. The environments are complex and submitted to extreme condition. They obtain their food by ingesting the marine sediment that contains microorganisms, meiofauna, decaying organic debris, inorganic components, and dissolved organic matter. This situation lead to survival adaptation and production of secondary bioactive metabolites which are lack in other organisms [4, 5]. A. molpadioides is consumed by the locals at Pulau Langkawi either raw (as salad) or cooked for their general health benefits due to the presence of bioactive compounds in their body wall such as triterpene glycosides, chondroitin sulphates, and sterols. A. molpadioides has been proven rich in vitamins and minerals [3]. *For correspondence: nurzafirah@ums.edu.my Received: 10 Nov. 2022 Accepted: 26 Dec. 2022 © Copyright Lambuk. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.