Isolation and Screening of the Lactic Acid Bacteria from Pickled Eucheuma SP Solution

The roles of the lactic in the food industries are popularly established for quite a long time. These bacteria are typically involved in a large number of spontaneous food fermentations such as cheese, yoghurt, butter and kimchi. Despite its popularity, very limited studies have been focused on the pickling of seaweeds; hence, this study aimed to isolate and screen the lactic acid bacteria (LAB) from pickled Eucheuma sp. solution. Specifically, this characterized the bacterial isolates using the biochemical tests. Eucheuma, a red alga obtained from Guimaras, Philippines was pickled using the procedure described by Hermes-Espejo (2005). For the purpose of characterizing and identifying the different lactic acid bacteria from the pickled samples, various biochemical tests were carried out. The different biochemical tests conducted included Gram staining reaction, Oxidative – Fermentation Glucose test, Catalase test and Arginine Dihydrolase test. Findings of the current study revealed that the three colonies of lactic acid bacteria isolated from the pickled seaweeds were from the genus Leuconostoc and Lactobacillus. Leuconostoc is heterofermentative lactic acid bacteria because it uses a combination of the pentose phosphate and phosphoketolase pathways. For many foods, such as fruit juice or milk products, Leuconostoc can contribute to the off flavors due to diacetyl production. Lactobacillus, on the other hand, is commonly found in many fermented food products as well as anaerobic plant matter. This can produce a variety of products from fermentation due to a large pyruvate-dissipating potential. Isolates which were confirmed as lactic acid bacteria in this study should be subjected to the appropriate molecular tools in order to compare with the results of the biochemical tests. The activities and the mechanisms of the Lactobacillus and Leuconostoc should be studied in the pickled seaweed products.