Predicting glycogen concentration in the foot muscle of abalone using near infrared reflectance spectroscopy (NIRS).

Near infrared reflectance spectroscopy (NIRS) was used to predict glycogen concentrations in the foot muscle of cultured abalone. NIR spectra of live, shucked and freeze-dried abalones were modelled against chemically measured glycogen data (range: 0.77-40.9% of dry weight (DW)) using partial least squares (PLS) regression. The calibration models were then used to predict glycogen concentrations of test abalone samples and model robustness was assessed from coefficient of determination of the validation (R2(val)) and standard error of prediction (SEP) values. The model for freeze-dried abalone gave the best prediction (R2(val) 0.97, SEP=1.71), making it suitable for quantifying glycogen. Models for live and shucked abalones had R2(val) of 0.86 and 0.90, and SEP of 3.46 and 3.07 respectively, making them suitable for producing estimations of glycogen concentration. As glycogen is a taste-active component associated with palatability in abalone, this study demonstrated the potential of NIRS as a rapid method to monitor the factors associated with abalone quality.

Prospects of using marine actinobacteria as probiotics in aquaculture.

Chemotherapeutic agents have been banned for disease management in aquaculture systems due to the emergence of antibiotic resistance gene and enduring residual effects in the environments. Instead, microbial interventions in sustainable aquaculture have been proposed, and among them, the most popular and practical approach is the use of probiotics. A range of microorganisms have been used so far as probiotics, which include Gram-negative and Gram-positive bacteria, yeast, bacteriophages, and unicellular algae. The results are satisfactory and promising; however, to combat the latest infectious diseases, the search for a new strain for probiotics is essential. Marine actinobacteria were designated as the chemical factory a long time ago, and quite a large number of chemical substances have been isolated to date. The potent actinobacterial genera are Streptomyces; Micromonospora; and a novel, recently described genus, Salinispora. Despite the existence of all the significant features of a good probiont, actinobacteria have been hardly used as probiotics in aquaculture. However, this group of bacteria promises to supply the most potential probiotic strains in the future.