NOVELTY - An isolated, hydrogen producing microorganism comprising a 16S rDNA sequence containing a sequence with more than 87% homology to a defined sequence of 671 bp (SEQ ID No: 1), given in the specification, is new.    USE - The microorganism is useful for producing molecular hydrogen; for increasing microbial hydrogen gas production; for collecting extraction and fermentation end- or by-products of a microorganism; for extracting fermentative microbial by- or end-products; and for producing high amounts of microalgal biomass and oil (all claimed).    ADVANTAGE - The present invention provides economical and sustainable bio-fuel production utilizing photosynthesis-performing life forms, such as green algae and cyanobacteria. More specifically, it provides microalgal oil production from fermentation waste streams for economical and sustainable industrial scale bio-diesel production. The processed bacterial fermentation waste streams are used as low cost carbon- and nitrogen-containing feedstock to achieve high microalgal biomass and oil production.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are: (1) a derivative or mutant of the microorganism above comprising a 16S rDNA sequence containing a sequence with more than 87% homology to SEQ ID No: 1; (2) a method of producing molecular hydrogen (H2) by culturing the microorganism above under conditions allowing hydrogen production; (3) a method of genetically engineering the microorganism above; (4) a method of mutagenizing the microorganism above by treating the microorganism with a mutagen, optionally further comprises screening the treated microorganism for increased hydrogen production rates and/or output; (5) a method of increasing microbial hydrogen gas production by incubating a hydrogen producing microorganism, or a microorganism above, in the presence of absorptive material; (6) a method of collecting extraction and fermentation end- or by-products of a microorganism by incubating the microorganism in the presence of absorptive material; (7) a method of culturing a microorganism by incubating the microorganism in the presence of absorptive material; (8) a method of extracting fermentative microbial by- or end-products by incubating a microorganism in the presence of absorptive material and growth media, separating the absorptive material from the growth media, and extracting the fermentative microbial by- or end-products from the absorptive material; and (9) a method of producing high amounts of microalgal biomass and oil by cultivating a green microalga belonging to the Chlorella species under ambient light conditions or in the dark in a cultivation medium containing a defined volume of processed bacterial fermentation waste, or a waste produced by a method of (5), and recovering microalgal oil from it.