The Life of Cyanobacteria Algae – Diala's Biology Blog

Welcome back to our discussion on algae! This week we will be focusing on algae as a eukaryote and explore its life cycle. Algae can be prokaryotic organisms as well as microbial eukaryotes. We will focus on cyanobacteria, also known as prokaryotic blue-green algae. Cyanobacteria contain chlorophyll a, which is the same photosynthetic pigment that plants use; in fact, the chloroplast in plants is a symbiotic cyanobacterium. Cyanobacteria play an important role in the health and growth of many plants; they are important in the nitrogen cycle. These organisms are one of the few groups that can convert inert atmospheric nitrogen into nitrate or ammonia. These “fixed” forms of nitrogen help plants for growth. Cyanobacteria also form a symbiotic relationship with many fungi forming complex organisms called lichens.

Algae are capable of photosynthesis and produce their own food/nourishment by using sunlight and carbon dioxide. Most algae are photoautotrophs; they use the light to create energy to generate nutrients. However, there are some algae that obtain their nutrition from outside sources which make them heterotrophic. Some algae can generate “osmotrophy” which is the absorption of dissolved substances and some algae can generate “phagotrophy” which involves consuming bacteria or similar prey. Some algae can be auxotrophs which only need to obtain their nutrients from vitamins such as B12 complex or fatty acids.

Algae have the capability to reproduce through asexual, vegetative methods, or sexual reproduction. Asexual reproduction involves the production of a motile spore or binary fission. Vegetative methods involve mitosis cell division to produce identical offspring. Sexual reproduction involves the union of gametes through meiosis.