Murni Saptasari

Bioethanol production from algae Spirogyra hyalina using Zymomonas mobilis

ABSTRACT Algae Spirogyra have the potential to be developed as a raw material for bioethanol production. This study aims to determine the effect of the hydrolysis process of algae Spirogyra on total sugar production. The hydrolysis process of Spirogyra hyalina was carried out using a variation of heating duration and type of enzyme. This study also aimed to determine the effect of fermentation duration and the addition of nutritional fermentation on the reducing sugar, pH changes, microbial biomass and ethanol production from algae Spirogyra hyalina by using Zymomonas mobilis. The fermentation process was carried out in anaerobic conditions using a modified fermentor for 96 hours. Results showed the differences the hydrolysis process of algae Spirogyra hyalina affected on sugar levels. The highest sugar level was achieved by a combination of α-amylase and β-amylase enzymes. Fermentation duration and nutritional fermentation affected reducing sugar, pH substrate, microbial biomass and ethanol levels produced from the fermentation of algae Spirogyra by using Zymomonas mobilis.

Isolation of Flower Development Regulator Gene SEPALLATA 1 in Phalaenopsis amabilis (L.) Blume

Phalaenopsis amabilis (L.) Blume is an indigenous orchid species in Indonesia. This orchid has a white large flower. The large flower is caused by the existence of gene that has an important role in flower development. One of the genes is SEPALLATA 1. This gene is a member of superfamily MADS-Box gene. SEPALLATA 1 gene is a marker of primordial flower organ. This study aimed to isolate SEPALLATA1 gene from Phalaenopsis amabilis (L.) Blume by PCR using forward primer 5’-GCT-GGA-GCG-GAT-CGA-GAA-CA-3’and reverse primer 5’-TCA-TGC-AAG-CCA-ACC-AGG-TG-3’ . This study successfully amplified 691 bp lengths of SEPPALATA1 fragment, lacking 20 bp upstream which consist its start codon. Keywords: Flower development regulation, Phalaenopsis amabilis (L.) Blume, SEPALLATA 1 gene.

Comparison of biomass production from algae Spirogyra hyalina and Spirogyra peipingensis

ABSTRACT This study aimed to determine the effects of the growth medium, water levels and incubation period on Spirogyra hyalina and Spirogyra peipingensis biomass. Completely randomized design (CRD) was used by varying the nutritional composition, water levels and incubation period. Culture was performed using a 12 h:12 h light:dark cycle using a TL 36 W fluorescent lamp with 3000 lux light intensity. The results show that the growth of the alga Spirogyra hyalina was faster than that of Spirogyra peipingensis. The highest yield obtained for Spirogyra hyalina was on day 10, whereas the highest yield obtained for Spirogyra peipingensis was on day 15. Both algae, i.e. Spirogyra peipingensis and Spirogyra hyalina, grew best in 20 cm of water level using Sulfahri-01 medium containing a high level of nitrogen.