Photosynthetic electron transport rate (ETR) in the littoral herb Launaea sarmentosa known as mole crab in Thailand

Photosynthesis Research - Launaea sarmentosa (Willd.) Sch. Bip ex Kunze (Asteracaeae) is a littoral sand dune herb found in the Indian Ocean region, used as a folk medicine and as a savory...     

Using DMSO for chlorophyll spectroscopy

DMSO (dimethyl sulphoxide, (CH₃)₂SO) is an alternative solvent for spectroscopic assay of chlorophylls (Chls) but has mainly been used on Chl a & b organisms. Here, we develop algorithms for the estimation of Chl a, b & c₁c₂, and d in DMSO solvent. The common unicellular green alga Chlorella sp. (Chl a & b) is used as an example of an oxygenic photo-organism with Chl a as the primary photosynthetic pigment and Chl b as the accessory Chl. The cyanobacterium Synechococcus is used as an example of organisms containing only Chl a. The diatom Chaetoceros sp. is used as the representative Chl a & c₁c₂ organism. The unusual chlorobacterium Acaryochloris marina has Chl d & a. Algorithms for use on mixed phytoplankton and algal mats (Chl a, b & c) were also developed. The algorithms for DMSO solvent are compared to those developed for 90% acetone as the benchmark solvent. DMSO solvent offers the advantages of low volatility, low toxicity, low flammability, biodegradability, and ease of transport and is an effective extractant of chlorophylls. However, there appear to be significant storage problems with DMSO extracts of chlorophylls because of its high freezing point (+18.4°C) and probable breakdown in chlorophylls in DMSO over several days.

     

DMSO formula for chlorophyll determination in dinoflagellates (Chl a + c2)

Journal of Applied Phycology - Zooxanthellae of corals, soft corals, and molluscs are endosymbiont dinoflagellates. Free-living dinoflagellates are also common in aquatic environments. Although...     

Lability of chlorophylls in solvent

Journal of Applied Phycology - DMSO (dimethyl sulfoxide, (CH3)2SO) is an alternative solvent for the spectroscopic assay of chlorophylls (Chl) but has mainly been used on Chl a and b organisms, but...     

Light absorptance of algal films for photosynthetic rate determinations

Journal of Applied Phycology - A Reflectance Absorptance Transmittance (RAT) meter, developed for routine measurements of Abtλ nm on leaves, was used to measure absorptance of algal films...