Effects of salinity and adhesive materials on the growth and adhesion of Amphora sp． HN08 under static conditions

Abstract:

Abstract:［Objective］To optimize the cultural conditions including adhesive materials and salinity for one tropical benthic diatom (Amphora sp． HN08)．［Methods］Two experiments were performed: (1) five adhesive materials including agar，glass，PVC plate，plastic film and nylon net were used to culture Amphora sp． HN08 HN08; (2) Amphora sp． HN08 was cultured under 6 salinity levels from 1 through 6%．The algal cells were harvested after 9 days treatments，and the biomass productivity，adhesive strength and pigments content of cells were examined.［Results］ For the adhesive materials experiment，cultures with glass and plastic plate showed the highest biomass production and the dry weight of cells reached to 3.64 g/m2．The adhesion strength level of cells on the glass plate was III degree，which means the cells were easy to be separated from the glass and dewatered by centrifugation． Salinity did not contribute significantly to the biomass production，while it significantly influenced the cells adhesion and pigments concentration． The adhesive strength levels of the cells under 3% or 4% salinity was IV degree，which led to an easy harvest process． While the cells cultured under high salinity (5% and 6% ) usually suspended in the medium and were difficult to be dewatered by centrifugation． Both chlorophyll a and carotenoid content of cells cultured with higher salinity (≥3%) are extremely higher (p＜0.01) than that with lower salinity (1% and 2%)．Chlorophyll a and carotenoid content of cells under 5% salinity was 26. 27% and 11. 11% by dry weight，respectively．［Conclusion］Taking the harvest and biomass production together，we think the optimal salinity for Amphora sp． HN08 was between 3% and 4%，and the glass plate was suitable for adhesive material．However，considering the cost and safety，the PVC plate is suggested to be used for biomass production．