1.The effectiveness of methanotrophic bacteria and Ochrobactrum anthropi to reduce CH4 and N2O emissions and to promote paddy growth in lowland paddy fields
Dalia Sukmawati ; Iman Rusmana ; Nisa Rachmania Mubarik
Malaysian Journal of Microbiology 2016;12(1):50-55
Aims: Paddy field is one of the sources of greenhouse gasses such as methane (CH4) and nitrous oxide (N2O), which
causes global warming and other negative effects in agricultural sector. An alternative to optimize paddy productivity and
reduce emissions of CH4 and N2O is by using methanotrophic bacteria and Ochrobactrum anthropi BL2.
Methodology and results: This study consisted of two parts, i.e. positive control and experimental treatments. Positive
control consisted of 250 kg/ha NPK inorganic fertilizer NPK (15:15:15) (100% of the recommended normal dose) without
any methanotrophic bacteria. Meanwhile the experimental treatment consisted of 50 kg/ha inorganic fertilizers NPK
(20% of the recommended normal dose) with methanotrophic bacteria (Methylocystis rosea BGM 1, M. parvus BGM 3,
Methylococcus capculatus BGM 9, Methylobacter sp. SKM 14) and N2O reducing bacteria (Ochrobactrum anthropi BL2).
Using weight indicator of 1000 grams, all the bacteria are capable of increasing paddy productivity by 42.07%, compared
to conventional method which can only increase the productivity by 2.51% (Cepy and Wangiyana, 2011). The increasing
productivity and growth of paddy plants were due to the nitrogen fixation activity of M. rosea BGM 1, M. capculatus BGM
9, and Methylobacter sp. SKM 14. In the experimental treatment using bacteria, the emission of CH4 and N2O was
reduced with the highest CH4 and N2O sinks of 24018.8 mol CH4/day/ha and 68.48 mol N2O/day/ha, respectively.
However, the positive control treatment with 100% of the recommended fertilizer dose showed the highest CH4 and N2O
emissions which were up to 74346.45 mol CH4/day/ha and 26.21 mol N2O/day/ha, respectively.
Conclusion, significance and impact study: All the methanotropic bacteria and O. anthropi BL2 are significantly
increase paddy production, compared to positive control treatment. The addition of bacteria in paddy fields results in CH4
and N2O sinks.
Ochrobactrum anthropi
2.Identification of phylloplane yeasts from paper mulberry (Broussonetia papyrifera (L.) L'Hér. ex Vent.) in Java, Indonesia
Dalia Sukmawati ; Ariyanti Oetari ; Dian Hendrayanti ; Mega Atria ; Wellyzar Sjamsuridzal
Malaysian Journal of Microbiology 2015;11(4):324-340
Aims: Broussonetia papyrifera (Saeh plant) has many qualities, the inner bark was the material for ‘dluwang’ papers on
which Indonesian historical manuscripts were written, and the leaves have bioactive constituents of medicinal value, and
antifungal activities. We investigated the diversity of yeast species associated with leaves from 6 months and 1.5 yearold
plants, which is prerequisite to understand the phylloplane yeasts and plant interaction.
Methodology and results: The yeasts were isolated from fresh leaves by washing and membrane filtration methods. A
total of 16 leaf samples of 6 months and 1.5 year-old plants were collected from four locations in Java, Indonesia, and
2,543 yeast isolates were obtained. Based on similarity of colony morphology, 82 representative yeast isolates were
selected and identified based on the sequence analyses of internal transcribed spacer (ITS) regions of rDNA. The
identification result showed that they consisted of 17 genera and 32 species. Thirty six of representative yeast isolates
belong to 11 genera (18 species) of the phylum Ascomycota and forty six isolates belong to 6 genera (14 species) of the
phylum Basidiomycota. Phylogenetic trees showed that the yeast isolates are phylogenetically diverse and distributed in
the phyla of Ascomycota (classes Saccharomycetales and Dothideomycetes) and Basidiomycota (classes
Microbotryomycetes, Tremellomycetes, and Ustilaginomycetes).
Conclusions, significance and impact of study: The phylloplane yeasts of B. papyrifera (Saeh plant) were
taxonomically heterogeneous. This is the first report of the isolation and identification of phylloplane yeasts from B.
papyrifera. Phylloplane yeasts may possess antagonistic activity to fungal plant pathogens in their natural habitats.
Yeasts
4.Identification of pathogenic bacteria on the salted fish Lutjanus vivanus in Sorong City of West Papua
Sukmawati ; Fatimah Hardianti ; Sipriyadi ; Isna Rasdianah Aziz
Malaysian Journal of Microbiology 2019;15(3):237-244
Aims:
Fisheries-based food is needed by humans as a protein source, one of which is salted fish Lutjanus vivanus. Market demand for this product in Indonesia is quite high. The aim of the study was to identify pathogenic bacteria in salted fish L. vivanus.
Methodology and results:
The method used in this study was descriptive method including pathogenic test, bacterial genomic DNA isolation based on 16 sRNA gene using prokaryotic specific primers, namely 63f forward primer (5′-CAG GCC TAA CAC ATG CAA GTC-3′) and reverse 1387r primer (5′-GGG CGG WGT GTA CAA GGC-3′). The results of this study indicated pathogenic bacteria in salted fish L. vivanus with pathogenic activity of α hemolytic and β hemolytic. The bacteria were identified as Serratia marcescens strain ZK2 16S for isolate KS and Bacillus altitudinis strains A-19 16S for isolate LG.
Conclusion, significance and impact of study
In salted fish L. vivanus in the Sorong city, West Papua, it was obtained Serratia marcescens strain ZK2 16S with total hemolytic activity and B. altitudinis A-19 16S strain with partial hemolytic activity.