Cold Storage of Six Marine Benthic Diatoms Native to the Mexico Pacific Coast

Abstract

Cultures of six benthic diatoms were maintained in the dark to measure their viability and biochemical composition after 8 wk of storage at low temperature (4 C) in darkness by refrigeration. Cell density, growth rate, and viability for each benthic diatom changed significantly after storage. Significant differences were observed with regard to cell size (length and width) of Nitzschia laevis, Navicula sp., and Amphora tenerrima as a result of storage. In general, the proximal composition of the benthic diatom cultures changed after week 1 of storage and decreased after week 4 of storage for all the diatoms. These results demonstrate that under 1-4 wk of storage these diatoms maintain their viability and had changes in their proximal composition in species-specific responses. Storage of preserved live microalgae cells is an alternative technique that can be used to reduce the need for continuous maintenance of live cultures and can provide live feed stock for aquaculture applications.

Photosynthetic and Biochemical Effects of Cold Storage on Marine Benthic Diatoms of the Mexican Pacific Coast

“…The AFW of N. incerta did not change but decreased in the other diatoms throughout storage. The changes in cell density, growth rate, and AFW of the four diatoms were similar compared with those of N. incerta after 4 wk of cold storage (Núnez‐Zarco and Sánchez‐Saavedra 2011). However, the growth rate of the diatoms was lower versus those of fresh cultures in other studies (without refrigerated storage) (Correa‐Reyes 2001; Aguilar‐May 2002; Carbajal‐Miranda 2002).…”

“…Another important task in culturing microalgae is continuous maintenance, in which cells are transferred to new medium prior to attaining the stationary growth phase (usually weekly); this step depends on the specific growth rate and culture conditions. The refrigeration of live microalgae (4 C in darkness) is an alternative method to reduce the time that is needed for continuous maintenance of live microalgae cultures (Cañavate and Lubián 1997; Chen 2001; Ponis et al 2008; Núnez‐Zarco and Sánchez‐Saavedra 2011).…”

Growth of Red Abalone, Haliotis rufescens, Fed Cold‐stored Benthic Diatoms

“…However, the cell density of the biofilm was not measured in this work. In previous studies related to diatoms cold‐stored for a period of 8 wk, it was found that the cells kept their viability to grow and increase the cell density when used as inoculum for new cultures (Núñez‐Zarco and Sánchez‐Saavedra ).…”

“…Four marine benthic diatom species were obtained from the collection of the Biology and Culture of Microalgae Group, Department of Aquaculture, Center of Scientific Research and Higher Education at Ensenada (CICESE) -Navicula sp., Navicula incerta, Nitzschia thermalis var. minor, and Nitzschia laevis -which were selected based on their biological characteristics, as described by Núñez-Zarco and Sánchez-Saavedra (2011). Diatoms were grown in monospecific, nonaxenic batch cultures in 2 L of f/2 medium (Guillard and Ryther 1962).…”