Optimizing Carbon/Nitrogen Ratio for Biosurfactant Production by a Bacillus subtilis Strain

Optimizing Carbon/Nitrogen Ratio for Biosurfactant Production by a Bacillus subtilis Strain

R. R. FONSECA,1 A. J. R. SILVA,2 F. P. DE FRANÇA,1 V. L. CARDOSO,3 AND E. F. C. SÉRVULO*,1

Abstract

A Bacillus subtilis strain isolated from contaminated soil from a refinery

has been screened for biosurfactant production in crystal sugar (sucrose)

with different nitrogen sources (NaNO3, (NH4)2SO4, urea, and residual

brewery yeast). The highest reduction in surface tension was achieved

with a 48-h fermentation of crystal sugar and ammonium nitrate.

Optimization of carbon/nitrogen ratio (3, 9, and 15) and agitation rate (50,

150, and 250 rpm) for biosurfactant production was carried out using complete

factorial design and response surface analysis. The condition of C/N

3 and 250 rpm allowed the maximum increase in surface activity of biosurfactant.

A suitable model has been developed, having presented great

accordance experimental data. Preliminary characterization of the bioproduct

suggested it to be a lipopeptide with some isomers differing from

those of a commercial surfactin.

Index Entries: Biosurfactant/production; crystal sugar; lipopeptide; surfaceactive substances; surfactin; Bacillus subtilis.

Monoclonal antibodies specific to haemocytes of black tiger prawn Penaeus monodon

Monoclonal antibodies specific to haemocytes of black tiger prawn Penaeus monodon

P. Winotaphan et al. / Fish & Shellfish Immunology 18 (2005) 18 9-198

Abstract

Monoclonal antibodies specific to haemocytes of Penaeusmonodon were generated from a mouse immunized with amixture of SDS-treated and formalin-fixed haemocytes. Hybridoma clones were selected by immunohistochemistry against fixed haemocytes, heart, lymphoid organ, and haemopoietic tissue, andWestern blot against haemocyte extract and haemolymph. Sixteen monoclonal antibodies specific to haemocytes were obtained and could be divided into six groups according to their binding capacities to various haemocyte proteins in Western blot analyses, 102, 43, w20, 61, 175 and w230 kDa, and their differences in recognition of haemocyte sub-populations. The first group of antibodies strongly recognized a small subset of semi-granulocytes (SG) and hyalinocytes (H) but occasionally stained lightly a very small population of granulocytes (G). The antibodies also bound to a group of cells in haemopoietic tissue as well as cells located at the inner layers of the tubules in the lymphoid organ but not in the spheroid. The second group of antibodies strongly bound to a large sub-population of Gand SG with coarse granules but did not bind to most of the H. This group of antibodies also cross-reacted with cells in the outer layer of the tubules in the lymphoid organ. The third group of antibodies recognized all G and only a small portion of SG. The fourth, fifth and sixth groups bound to sub-populations of G, SG and Hin similar proportions. None of the antibodies showed any cross-reactivity to other components in haemolymph. The common antigens recognized by the first and the second groups of antibodies in the haemopoietic tissue and the lymphoid organ may reflect relationships among these organs in the development of the sub-populations of G and SG. Haemopoietic tissue may be the site for haemocyte production and the lymphoid organ may be the site for further differentiation of at least two different lines of haemocytes.

2004 Elsevier Ltd. All rights reserved.

Keywords: Granulocyte; Haemocyte; Haemopoietic tissue; Hyalinocyte; Lymphoid organ; Monoclonal antibody; Penaeus monodon; Semi-granulocyte

Baca jurnal selengkapnya: 

TINGKAH LAKU BULU BABI DI PADANG LAMUN

TINGKAH LAKU BULU BABI DI PADANG LAMUN

Oleh

Aznam Aziz*)

ABSTRACT

LIVING HABITS OF REGULAR URCHINS ON SEAGRASS BED. The regular urchin (Echinoidea) and herbivorous fishes are abundant, conspicuous and important consumers of seagrasses in seagrass beds. Some urchins are commonly associated with seagrass beds, namely Tripneustes gratila, Tripneustes ventricosus, and Lytechinus variegatus. The sea urchin as Tripneustes gratilla grazes on seagrasses especially during the day time, but some of them graze both during the day and the night. The nutritional ecology, daily activities, covering activities, as well as predator habits are discussed in this article.

ABSTRAK

Landak laut (Echinoidea) dan ikan herbivora yang melimpah adalah konsumen utama dan penting dari lamun di padang lamun. Beberapa bulu babi yang umumnya terdapat di padang lamun, yaitu Tripneustes gratila, Tripneustes ventricosus, dan Lytechinus variegatus. Landak laut seperti Tripneustes gratilla merumput pada padang lamun terutama selama siang hari, tetapi beberapa dari mereka merumput baik siang hari dan malam. Ekologi, aktivitas sehari-hari, kegiatan, serta kebiasaan makan  dibahas dalam artikel ini.

Bulu babi ~ wikipedia

Oseana XIX No. 4: 35-43   ISSN 0216-1877

*) Balai Penelitian dan Pengembangan Biologi Laut, Pusat Penelitian dan Pengembangan Oseanologi - LIPI, Jakarta


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