This paper presents a review on Botryococcus braunii, a cosmopolitan green colonial microalga characterised by a considerable production of lipids, notably hydrocarbons. Strains like wild populations of this alga differ in the type of hydrocarbons they synthesise and accumulate: (1) n-alkadienes and trienes, (2) triterpenoid botryococcenes and methylated squalenes, or (3) a tetraterpenoid, lycopadiene. In addition to hydrocarbons and some classic lipids, these algae produce numerous series of characteristic ether lipids closely related to hydrocarbons. This review covers the algal biodiversity, the chemical structures and biosynthesis of hydrocarbons and ether lipids and the biotechnological studies related to hydrocarbon production.

Botryococcus braunii: a rich source for hydrocarbons and related ether lipids

Alkadiene- and botryococcene-producing races of wild strains of Botryococcus braunii

Summary

Blue-green algae dominated the open waters of Lake Victoria during an algal bloom between February and August 1986. Microcystis sp. accounted for more than 90% of the bloom organisms with algal counts reaching a high density of 34,000 colonies per ml and chlorophyll a concentration at 77-6 μg 1-1. Secchi disc visibilities and the 1 % light penetration were reduced to 0–2 m and 1 m, respectively. The release of nutrients from river inflows, from upwelling and from sediments into the euphotic zone, coupled with high temperatures, produced the observed blooms. The blooms subsequently declined as a result of physical flushing, temperature reduction associated with the rainy season and nutrient exhaustion.



Resume

Les algues bleues et vertes ont predomine dans les eaux libres du Lac Victoria durant une eclosion massive d'algues, de fevrier a aout 1986. Microcystis representait plus de 90% des organismes eclos, avec des chiffres atteignant plus de 34,000 colonies par ml et une concentration en chlorophylle de 77-6 mug 1-1. La visibilite du disque de Secchi et la penetration d'un pour cent de la lumiere etaient reduits a 0–2 m et 1 m respectivement. l'apport de nutriments par les rivieres, par les sources et par les sediments vers la zone exposee a la lumiere, combine avec de hautes temperatures a cause le phenomene observe. Cette explosion diminua ensuite a cause de phenomenes physiques: une reduction de temperature associee a la saison des pluies et a l'epuisement des nutriments.

Observations on blue-green algal blooms in the open waters of Lake Victoria, Kenya

A numerical simulation of the role of zooplankton in C, N and P cycling in Lake Kinneret, Israel

Goldman, McCarthy & Peavey (1979b) argued that growth rates of phyto-plankton in apparently oligotrophic ocean waters may near maximal Their hypothesis was succinctly restated by Goldman (1980): ‘…the chemical composition of phytoplankton is extremely variable under exacting laboratory conditions of nutrient limitation and approaches the ‘Redfield’ proportions (C:N:P of 106:16:1) when neither nitrogen nor phosphorus is limiting so that near maximal growth rates are attained In marine surface waters the chemical composition of particular matter often is in the Redfield proportions, thus implying that natural phytoplankton growth rates may be close to maximal’ We argue on theoretical, experimental and observational grounds that this implication may not necessarily be correct

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315400050566

N.J. Patni

Papers

Some observations on the green planktonic alga, Botryococcus braunii and its bloom form

The relationship between nutrient status and chemical composition of Peridinium cinctum during the bloom in Lake Kinneret