Rapid indicators for monitoring the health of Chlamydomonas nivalis biomass during preservation

Abstract

Microalgae are photosynthetic microorganisms that have increasingly attracted interest in the last decade due to their potential for industrial applications. One crucial aspect for the industrial-scale valorisation of algae biomass concerns the quality control during its preservation before being treated to obtain the end-product. Monitoring biomass quality is essential and can be potentially accomplished with the aid of specific biochemical indicators called biomarkers. In this context, the main aim of this work was to identify potential indicators of microalgae biomass viability that could be used as markers of its quality during storage/preservation for commercial operations. The health status of a suspension of Chlamydomonas nivalis was assessed at 4 ºC and 25 ºC during 10 days of storage. The use of the pulse-amplitude-modulation technique, based on chlorophyll fluorescence, was a valuable indicator of the culture viability. The measurement of DNA and of chlorophyll in the supernatant, indicative of cell lysis, also provided satisfactory results; in the case of the DNA, the limit of detection was 3.9 µg DNA·mL−1. The effect of different concentrations of a well-known and cheap preservative, acetic acid, was also evaluated at 4 ºC. This work identified three suitable biomarkers to be used as rapid indicators of the quality of the microalgal suspension prior to its reception for biorefinery activities.

Estimating Biomass and Vitality of Microalgae for Monitoring Cultures: A Roadmap for Reliable Measurements

“…Moreover, new technologies and cheap components enabled the development of inexpensive battery-operated, handheld devices that also pave the way for use by non-academic institutions. Although Fv/Fm is not suitable for calculating growth rates and modelling primary productivity [ 67 ], it is a valuable biomarker to gain insight into the health status of oxygenic photoautotrophs during active growth [ 10 , 12 , 14 , 68 , 69 ] and storage [ 70 ].…”

The Impact of Non-Concentrated Storage on the Centrifugation Yield of Microchloropsis gaditana: A Pilot-Scale Study

“…This was previously shown to already begin at the end of the cultivation period in the case of Tetradesmus lagerheimii (formerly Scenedesmus acuminatus) [21], Chromochloris zofingiensis (formerly Chlorella zofingiensis) [22], and Dunaliella salina (Chlorophyta) [23], and can be expected to become more prominent during storage. Indeed, cell lysis was cited to explain the appearance of extracellular chlorophyll and algal DNA during the storage of Chlamydomonas nivalis concentrates obtained through batch centrifugation [24], and to explain the strong increase in cell permeability during the storage of Nostoc flagelliforme (Cyanobacteria) concentrates [25]. The extent to which shear stresses lead to cell rupture depends on the species used [26] and especially on cell wall rigidity [8], which, in turn, may depend on environmental conditions such as medium salinity [27].…”

Indoor Plant Soil-Plant Analysis Development (SPAD) Prediction Based on Multispectral Indices and Soil Electroconductivity: A Deep Learning Approach

“…Precise assessment and prediction of plant health and vitality have emerged as critical variables in ensuring optimal crop development and effective resource management in the context of modern horticulture [5,6]. Measurement of chlorophyll concentration is a key indicator used to assess overall plant health due to its direct relationship with photosynthetic activity [7]. In addition, phytoremediation, the use of plants to remove toxins from indoor environments, is becoming increasingly important [8].…”