Vol 4 (2010)

Table of Contents

Characterization of marine yeasts isolated from different dubstrates collected In Calatagan, Batangas

Research Paper, pages 1-11

by Carly Simon P. Ramirez, Connel O. Go, Sophia Angelica S. Hernandez, Hanah I. Ruiz, Maureen B. Sabit1 And Thomas Edison E. Dela Cruz

Abstract

Marine yeasts can be isolated from various substrata. Their potential industrial application merits a thorough study of these microorganisms. Thus, our research study aimed to isolate and characterize marine yeasts from several substrata collected from Calatagan, Batangas. Marine yeasts were isolated using enrichment culture of seawater, marine sediments, and living and decaying seagrasses and seaweeds on Glucose-Yeast Extract-Peptone broth (GYPS) supplemented with 33 g/L marine salts. Following incubation at room temperature, a total of 13 yeast strains were isolated. Most of the marine yeasts were obtained from either living or decaying seagrasses. Growth on GYP Broth with and without salt showed that six out of the 13 isolates were able to grow in the presence or absence of marine salts. Characterization of the isolated marine yeasts was done using the conventional morphological and biochemical methods and modern molecular techniques. All marine yeasts have cream-colored, circular and convex colonies with entire margin. The cells were spherical with a size range of 2.5 – 12.5 μm. They utilized galactose, maltose, sucrose, trehalose, xylose, sorbitol, N-acetyl-glucosamine and 2-keto-gluconate. Only one isolate (PCL08-LG04) utilized glycerol, arabinose, cellobiose, and raffinose. Comparison of the API 20C Aux profiles with the API database indicated that the isolated marine yeasts have affinity to the genus Candida. Gene sequence analysis of their ITS 1 and 2 regions of nuclear rDNA identified the isolates as Candida tropicalis and Pichia carribica.

Keywords: marine yeasts, enrichment culture, polyphasic taxonomy, gene sequence analysis

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Characterization and identification of high cellulase-producing bacterial strains from Philippine mangroves

Research Paper, pages 13-20

by Nik Shawn C. Tabao And Rosario G. Monsalud

Abstract

Five promising cellulase-producing bacterial strains from soils collected from various mangrove sites in the country were characterized phenotypically and identified using conventional approach and, alternatively, by rapid identification through the Analytical Profile Index (API) system. They were identified as follows: BBCS-11 as Bacillus cereus; BBCS-14 as Bacillus licheniformis; BOrMGS-2 and BOrMGS-3 as Bacillus pumilus; and BBoB2L2-2 as Bacillus sp. The results generated from this study provided data regarding species of Bacillus producing cellulase enzyme and impart additional knowledge regarding the bacterial diversity of mangrove forests in the Philippines.

Keywords:Bio-prospecting, Conservation, Bacterial Diversity, Mangrove Forests

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Leaf architecture of selected species of Malvaceae sensu APG and its taxonomic significance

Research Paper, pages 21-54

by Allen Anthony P. Laraño, And Inocencio E. Buot Jr.

Abstract

The leaf architecture of Malvaceae sensu APG was examined and characterized to determine if it can be used in classification of the family and the identification of its species. Forty species were observed, measured and described. A dichotomous key was constructed based solely on leaf architecture characters.

The dichotomous key indicated that leaf architecture characters can be used in distinguishing some species of Malvaceae sensu APG. Some basic leaf architectural characters can also be used in describing certain clades within the family.

It is recommended that specimens are collected personally instead on relying on available specimens in the herbarium. Preparation of leaf skeletons through clearing method can also be done in future studies. Increase of sample size is also recommended.

Keywords: leaf architecture, APG, classification
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Molecular confirmation on the phylogenetic position of the genus Clemensiella Schltr. In Marsdenieae (Apocynaceae – Asclepiadoideae)

Research Paper, pages 55-66

by Arleen L. Buera, Ophelia S. Laurente, Bismark Oliver C. Lemana And Grecebio Jonathan D. Alejandro

Abstract

The Philippine Marsdenieae (Apocynaceae-Asclepiadoideae) comprises a total of seven genera including the imperfectly known Clemensiella Schltr. Due to its unique morphology, the position of the small genus in the tribe Marsdenieae of Asclepiadoideae was previously in question. In this first molecular study of Clemensiella, the internal transcribed spacer (ITS, nrDNA) region of three isolates were newly generated and analyzed together with previous published sequences. The present aims to assess the phylogenetic positon, monophyly and closely-related genera of Clememsiella. The three Clemensiella isolates yielded a total of 630 to 642 base pairs (bp) and the average GC content ranged from 63.21% to 63.86%. Based on the strict consensus tree, the monophyly of Clemensiella is highly supported with BS = 100% and nested within the tribe Marsdenieae with BS = 61%. This study confirms the phylogenetic position of Clemensiella in Marsdenieae and its close relation to Dischidia and Hoya. Although the three Marsdenieae are distinct in their seed structures, they share common features in habit, inflorescence and corolla aestivation.

KEYWORDS: Clemensiella, ITS, Marsdenieae, Apocynaceae, Asclepiadoideae

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New dipterocarp species from the Philippines

Research Paper, pages 67-78

by Hermes G. Gutierrez, Justo P. Rojo And Domingo A. Madulid

Abstract

Four new species of plants under the family Dipterocarpaceae from the Philippines are here described: Hopea reynosoi Gut., Rojo & Madulid; Hopea santosiana Gut., Rojo & Madulid, Shorea arsorianoi Gut., Rojo & Madulid and Vatica mendozae Gut., Rojo & Madulid

KEYWORDS: Dipterocarpaceae, Hopea, Vatica and Shorea, Philippines

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Screening and optimization of cellulase production of Bacillus strains isolated from Philippine mangroves

Research Paper, pages 79-87

by Nik Shawn C. Tabao1 and Rosario G. Monsalud

Abstract

Two-hundred and twenty-five mangrove bacterial strains previouslyisolated from several mangrove areas in the Philippines were qualitativelyscreened for cellulase production and 154 were found to be capable of cellulase production. Among them, ten strains showed very strong positive cellulase activities, which were then quantified. Five with the statistically highest activities, specifically, BBCS-11, BBCS-14, BBoB2L2-2, BOrMGS-2, and BOrMGS-3, including Cellulomonas sp. BIOTECH 1240 (control), were further subjected to partial optimization studies. The effects of substrate, pH, incubation temperature and incubation time on cellulase productoin were determined. The cellulase activities (U mL-1) of the strains under optimized conditions were: 54.80 (Control); 56.60 (BBCS-11); 66.50 (BBCS-14); 50.33 (BBoB2L2-2); 51.04 (BOrMGS-2); and 48.70 (BOrMGS-3). The promising cellulase producers were previously identified: BBCS-11 as Bacillus cereus; BBCS-14 as Bacillus licheniformis; BOrMGS-2 and BOrMGS-3 as Bacillus pumilus; and BBoB2L2-2 as Bacillus sp.

KEYWORDS: DBio-prospecting, Conservation, Bacterial Diversity, Bacterial Enzymes, Mangrove Forests.

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Nomenclatural notes on some Philippine species of freshwater red algae

Review Paper, pages 89-94

by Lawrence M. Liao

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Philippine Journal of Systematic Biology ISSN 1908-6865