2.1.8.2. Absorbency Under Load (AUL) - BADA

One of the paper preparation processes from wood pulp is sulfite process ,in this process the
wood pulps introduce into the sodium sulfite solution in order to pre-delignification, so the
result of treatment will be lignosulfonate 60%, sugars 20% and other material 20% where
dominating sugars are glucose, galactose, mannose and xylose [13] .
One of the waste waters at this process is spent sulfite liquor as an undesirable and toxic
material. Trough water treatment processes zygomycetes use all sugars; pentoses as well as
hexoses. Toxic compounds such as hydroxymethylfurfural, furfural and acetic acid at high
concentrations in sodium sulfite solution prevent the growth of zygomycetes [13] .
1.4.1. Structure of Zygomycetes
The structure of zygomycetes cell is long branching filamentous (Hyphae) which are not divided
into numerous individual cells (nonseptate mycelium) and protoplasm of zygomycetes can flow
through out the tube-like structures. The component of cell wall is mainly chitosan (56-60%)
which is responsible for increasing of mechanical strength and shape of cell wall and rest
components are protein, triglycerides and mineral complexes of calcium [13] .
1.4.2. Cultivation of Zygomycetes
For cultivation of zygomycetes on spent sodium sulfite liquor (SSL) were used air-lift blowers
and cultivation consist of a 5 zygomycetes strain (zit 102) which was isolated from Indonesian
Tempe (a solid fermented Soya bean 'cake' which is widely consumed as a flavor meat substitute
in Indonesia), moreover recovered SSL after ethanol fermentation process by saccharomyces
cerevisiae was added to zygomycetes medium as a nutrient [14] .This composition contains high
nutritious value, but before adding of Rhizopuse oryzae to SSL and dilutions, the pH was
adjusted with ammonia and ammonium phosphate (pH 5-6.3) and to supply additional
nitrogen and phosphate source. Finally this solution was incubated at 36-38 o C [13] .
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