Characterization of Streptomyces sp. KB1 and its cultural optimization for bioactive compounds production

Monthon Lertcanawanichakul; Tuanhawanti Sahabuddeen

doi:10.7717/peerj.14909

Characterization of Streptomyces sp. KB1 and its cultural optimization for bioactive compounds production

PeerJ. 2023 Feb 24:11:e14909. doi: 10.7717/peerj.14909. eCollection 2023.

Authors

Monthon Lertcanawanichakul^{1

2}, Tuanhawanti Sahabuddeen³

Affiliations

¹ School of Allied Health Sciences, Walailak University, Thasala, Thaiburi, Nakhon Si Thammarat, Thailand.
² Food Technology and Innovation Research Center of Excellence, Walailak University, Thaiburi, Thasala, Nakhon Si Thammarat, Thailand.
³ Research Unit of Natural Product Utilization, Walialk University, Thaiburi, Thasala, Nakhon Si Thammarat, Thailand.

Abstract

Background: Bioactive compounds (BCs) from natural resources have been extensively studied because of their use as models in the development of novel and important medical and biopreservative agents. One important source of BCs is microorganisms, particularly terrestrial bacteria of the order Actinomycetales.

Methods: We characterized Streptomyces sp. KB1 by observing its morphology, physiology, and growth on different media using biochemical tests, optimizing cultural conditions by changing one independent variable at a time.

Results: Streptomyces sp. KB1 (TISTR 2304) is a gram-positive and long filamentous bacteria that forms straight to flexuous (rectiflexibile) chains of globose-shaped and smooth-surfaced spores. It can grow under aerobic condition s only at a temperature range of 25-37 °C and initial pH range of 5-10 in the presence of sodium chloride 4% (w/v). Therefore, it is considered an obligate aerobe, mesophilic, neutralophilic, and moderately halophilic bacteria. The isolate grew well on peptone-yeast extract iron, Luria Bertani (LB), and a half-formula of LB (LB/2), but could not grow on MacConkey agar. It utilized fructose, mannose, glucose, and lactose as its carbon source along with acid production and showed positive reactions to casein hydrolysis, gelatin liquefaction, nitrate reduction, urease, and catalase production. Streptomyces sp. KB1 (TISTR 2304) could produce the maximum number of BCs when 1% of its starter was cultivated in a 1,000 ml baffled flask containing 200 ml of LB/2 broth with its initial pH adjusted to 7 with no supplemental carbon source, nitrogen source, NaCl, or trace element at 30 °C, shaken at 200 rpm in an incubator for 4 days.

Keywords: Antibacterial activity; Bioactive compounds; Characterization; Luria-Bertani; Optimization; Streptomyces sp. KB1.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Actinomycetales*
Animals
Carbon
Caseins
Culture Media
Gastropoda*
Streptomyces*

Substances

Carbon
Caseins
Culture Media

Grants and funding

This research was supported by Plant Genetic Conservation Project Under the Royal Initiation of Her Royal Highness Princess Maha Chakri Sirindhorn (RSPG): WUBG-019/2564, WUBG-008/2565, RSPG 21-2566. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.