Aims: This study aimed to investigate the suitability and efficacy of various encapsulation media in bioencapsulating the probiotic Lactococcus lactis subsp. lactis in Artemia franciscana nauplii. The impact of the encapsulation media on nauplii survival and probiotic recovery was also determined. Methodology and results: Various encapsulation media (sodium alginate, palm oil, starch, gum Arabic and gelatin) were prepared by dissolving the respective media in artificial sea water. Each media was prepared in four different concentrations: 0.25, 0.5, 1.0 and 2.0 g/L. To determine the suitability of encapsulation media on the survivability of A. franciscana, survival rate (SR) of Artemia nauplii was determined after 8 hours post-encapsulation. Instar II stage Artemia nauplii at 1 nauplii per mL was used for each replicate. The result revealed that A. franciscana reached 100 % SR in the encapsulation media at ≤ 0.5 g/L. All media enabled > 23 % recovery of L. lactis subsp. lactis from encapsulated A. franciscana, which is similar (p > 0.05) to the recovery of free-cells (non-encapsulated) of L. lactis subsp. lactis. Noticeably in sodium alginate (E1) treatment, the total counts of L. lactis subsp. lactis in bioencapsulated A. franciscana were the highest among others, accounting for 2.44 × 107 CFU/mL per A. franciscana tissue homogenate. Conclusion, significance and impact of study: Artemia nauplii bioencapsulated with L. lactis subsp. lactis using 0.5 g/L sodium alginate as encapsulation medium has the highest SR for nauplii and bioencapsulation efficiency, respectively. This result provides a basic guideline for Artemia bioencapsulation in fish/shrimp larval culture.
Lactococcus lactis

Aims: This study is to isolate and characterize endophytic bacteria for potential industrial enzymes and antimicrobial activities against some human pathogens. Methodology and results: Mentha spicata, a local medicinal plant, was used to source for endophytes. The roots, stems and leaves of M. spicata were surface-sterilized to isolate the endophytic bacteria. The endophytic bacteria were subsequently characterized based on their 16S rRNA sequences. The endophytic bacteria were screened for both antimicrobial and enzymatic activities. We identified 15 isolates of 4 genus-Pseudomonas (7 species), Bacillus (3 species), Enterobacter (1 species) and Comamonas (1 species) with 97-100% similarity level. Isolates MSS-3 (Pseudomonas putida), MSR-4 (Pseudomonas pictorum), MSS-2 (Bacillus thuringiensis) and MSR-5 (Pseudomonas straminea) showed prominent antimicrobial activities against the pathogens tested with zones of inhibition between 6.3 to 15.3 ± 0.6 mm. All species examined have positive cellulase activities except Comamonas guangdongensis and only isolates of the Bacillus genus, Pseudomonas pictorum and P. argentinensis exhibited amylase activities. Conclusion, significance and impact of study: Our findings revealed potential therapeutic uses of the bioactive compounds of these bacteria endophytes against pathogens. Their enzymatic potential can also be of use in various industries.
Anti-Infective Agents