Category Archives: Volume 34 No. 2 (2012)

Fungi from Coastal Sediments as Potential Agents in Biodegrading Used Engine Oil

Author(s): Jayzon G. Bitacura, Arvin C. Balala and Pamela P. Abit


The use of microorganisms to decontaminate the environment loaded with oil pollutants is a beneficial option for bioremediation. This study aimed to isolate, characterize and identify oil-degrading fungi from the coastal sediments of the port area of Ormoc City, Philippines, and to evaluate and compare the oil-biodegrading capabilities of these fungi. Fungal isolates were subjected to an in-vitro biodegradation assay using used engine oil as substrate. Four species of filamentous fungi were isolated and identified down to genus level. The fungal isolates include three Aspergillus spp. and one Penicillium sp. Aspergillus spp. 1 & 2 were the most efficient in degrading and utilizing the used engine oil for growth. Aspergillus sp. 1 & 2 and Penicillium sp.had mean pH values of 6.286, 6.136 and 6.32, respectively. Highest mean percent fat loss on the media and highest mean dry weights were exhibited by Aspergillus sp. 2 (mean fat loss = 77.12% and mean dry weight= 0.24g) and Aspergillus sp. 1 (mean fat loss = 69.4% and mean dry weight = 0.21g). Filamentous fungi from the coastal sediments in the vicinity of Ormoc City port area could therefore be used as potential bioremediation agents in areas contaminated with petroleum oils.

Keywords : filamentous fungi, characterization, bioremediation, oil pollution

Annals of Tropical Research 34(2):112-125(2012)

Water Quality of Mantayupan River in Barili, Cebu, Philippines

Author(s): Alfredo C. Neri1, Virgie P. Wee1 and Glenn B. Hoyohoy2


The Mantayupan River is among the most important sources of water in Cebu, Philippines. This study was conducted to evaluate the physical, chemical, and microbiological characteristics of this river ecosystem and monitor the uses of its water. Results showed that Mantayupan river’s overall water quality index (WQI) indicated only a “medium or average water quality” at the head water all the way down the river channel during dry season. In the rainy season, the river’s WQI scaled a “good water quality” at the head water and falls but declined to “medium or average water quality” at its downstream. Results indicated that bathing or any recreational water contact activity is safe only during the wet season at the head water up to the Mantayupan falls but not after and until the downstream. However, the denser population of coliforms along the river indicates that Mantayupan falls situated closer to the head water than the downstream is not suitable for bathing and any recreational water contact activity during both seasons.

Keywords : Water quality, river pollution, water uses, eco-tourism

Annals of Tropical Research 34(2):95-111(2012)

Conditions Surrounding Publication Performance of Faculty Members of Two Selected Higher Education Institutions In Eastern Visayas, Philippines

Author(s): Niño Antonio P. Villalino and Editha G. Cagasan


In the Philippines, only a small percentage of research is published in scientific publications. This study aimed to find out the conditions surrounding publication performance of faculty members in universities in Eastern Visayas. Data were gathered through in-depth interviews from 16 respondents with high publication performance (HPP) and low publication performance (LPP) and through analysis of secondary data. Using the grounded theory approach, a theoretical model was generated. Results showed that the conditions leading to HPP were: (1) favorable research environment characterized by low workload in instruction, availability of funding support and research facilities, access to research mentors, and availability of publication incentives; (2) exposure to research during graduate and undergraduate studies; (3) strong peer influence; (4) positive attitude towards publication of research results; and (5) beliefs in the positive consequences of publishing. On the other hand, the conditions leading to LPP were: (1) unfavorable research environment characterized by high workload for instruction, lack of funding support and research facilities, and lack of access to research mentor; (2) academic background not research-oriented; (3) low level of peer influence; (4) negative attitude towards publishing research results; and (5) availability of other options to disseminate research results. Research findings imply that if given a favorable research environment, faculty members can be productive in research and publishing of research results.

Keywords : Scientific publication, research environment, peer-reviewed publications, HEI

Annals of Tropical Research 34(2):75-94(2012)

Development of Self-pollinating and Early-bearing Philippine Makapuno (Cocos nucifera L.) Hybrids

Author(s): Tessie C. Nuñez and Edwin T. Ocoy


The makapuno-bearing character found only in the cross-pollinated Laguna Tall coconut variety and the self-pollinating character of dwarf coconuts were combined into new makapuno genotypes through hybridization to limit cross pollination which is a problem among tall makapuno palms. F1 hybrids between Coconiño (CÑO) and tall Makapuno (TMAC) and Tacunan (TAC) x TMAC were early-bearing with high intraspadix overlapping percentages of 85.7% and 70.90, respectively. Mean makapuno yield was 26.8% in CÑO x TMAC and 28.2% in TAC x TMAC indicating the presence of high degree of self-pollination and the dominance of the gene for the trait. ln vitro grown homozygous F2 makapuno palms started flowering at 24 months old. F2 CÑO x TMAC (VMAC 1) had a mean yield of 100% makapuno, 49 to 132 nuts/palm/year and nuts weighing 332 to 750g/dehusked nut. F2 MRD x TMAC (VMAC 2) yielded a mean of 97% makapuno, 63 to 163 nuts/palm/year and nuts weighing 288 to 1,180g each. F2 TAC x TMAC (VMAC5) had 95% makapuno, nuts weighing 736g to 1,975g/ dehusked nut. High makapuno yield of the F2 hybrids affirmed the dominance of the gene for self-pollination in coconut. Ten month-old nuts of the F2s had at least 18 mm thick meat and Lauric acid (C12) content ranging from 47.10% to 48.60%. The three F2 hybrids were registered with the National Seed Industry Council (NSIC) in 2008 as the first homozygous makapuno hybrids in the Philippines.

Keywords : soft-endospermed coconut, intraspadix overlapping, precocity, Lauric acid

Annals of Tropical Research 34(2):63-74(2012)

Chemical Composition and Pulp Properties of Abaca (Musa textilis Née) cv. Inosa Harvested at Different Stages of Stalk Maturity

Author(s): Luz O. Moreno1 and Calixto M. Protacio2


Given the increasing global demand for pulp, there is a need to look into the prospects of increasing fiber production and shortening the harvesting cycle of abaca without sacrificing the quality of fibers for pulp production. This study investigated the chemical and pulp properties of abaca cv. Inosa fibers harvested at different stages of stalk maturity to determine their suitability for pulp and paper production.
Fibers obtained from 8-10-month-old (immature) abaca cv. Inosa possessed the desirable chemical properties for pulping, namely; low lignin and ash content, high alpha-cellulose, holocellulose and hemi- cellulose contents; which are comparable with those obtained from intermediate and mature stalks. The average pulp yield, Kappa number, viscosity, tear index and breaking length of pulps from immature stalks were already comparable with those of mature fibers and were even higher than the mature fibers of Linawaan and Laylay cultivars. Fibers of abaca cv. Inosa obtained from immature stalks were thus, found suitable for pulp and paper production.

Keywords :abaca fibers, pulp and paper, chemical composition, stalk maturity

Annals of Tropical Research 34(2):45-62(2012)

Strong Sour Tamarind Flavor of Methyl-2,3,4- trihydroxyhexanoate, a new compound isolated from Leaves of Tamarindus indica, L. plays a role in plant defense mechanisms

Author(s): Suprana M. Biswas, Nabanita Chakraborty and Supriya Chakraborty


Flavoring compounds of plants play a significant role in plant defense mechanism. Compound responsible for strong sour tamarind flavor has been isolated and identified from Methanol fraction of tamarind leaves (TrMF). Chromatographic and spectral analyses of TrMF revealed the compound to be methyl 2,3,4- trihydroxyhexanoate. This compound showed a strong antioxidant activity as well as strong antimicrobial activity. It showed significant antioxidant activity with Ic50 value of 2.5μg/ml whereas tert-butyl-1-hydroxytoluene and ascorbic acid revealed 26.0μg/ml and 5.0μg/ml, respectively. It also revealed strong inhibitory activity against Aspergellosis disease-causing fungi namely; Aspergillus fumigatus, Aspergillus tamarii and Aspergillus niger at all concentrations. Streptococcus aureus and Escherichia coli were much more sensitive to methyl-trihydroxy-hexanoate at all concentrations than Pseudomonas aeruginosa. This pure compound exhibited concentration dependent inhibitory and stimulatory activity on rice seeds germination and seedling growth. It showed strong inhibitory activity up to 62.5ppm concentration and below this concentration the effect was stimulatory. Methyl- trihydroxyhexanoate exhibited wide range of defensive activity against microbes and crop seeds and also possesses potent antioxidative activity. Thus play an important role in plant defense mechanism and can be utilized as a valuable source of bio-herbicides and pesticides.

Keywords : Tamarind (Tamarindus indica L.), Tamarind flavor, Tamarind methanol fraction, Methyl 2,3,4-trihydroxyhexanoate, Biopesticide.

Annals of Tropical Research 34(2):26-44(2012)

Managing Rice Residues and Fertilization to Improve Nutrient Use and Productivity of Irrigated Lowland Rice

Author(s): Michelle B. Castillo1, Cezar P. Mamaril1, Erlinda S. Paterno2, Pompe C. Sta. Cruz3, Pearl B. Sanchez2 and
Rodrigo B. Badayos2


Two field experiments were conducted in two sites with different soil properties to determine the appropriate management of rice residues coupled with cultural practices, including land preparation and fertilization to improve the nitrogen use efficiency and productivity of irrigated lowland rice. The study showed that in general, mowing of rice stubbles and either plowing or rotavating the soil did not affect the plant nutrient uptake (PNU), grain and straw yields, and yield components. In 2010 dry season, the highest PNU, yield, and return on investment (ROI) were obtained from the Minus-one Element Technique (MOET)-based fertilization compared to Nutrient Manager (NM)-based. In contrast, NM-based treatments had higher agronomic (AEN) and physiological efficiency of fertilizer nitrogen (PEN) due to higher level of N applied using the MOET compared to NM-based fertilization. In 2010 wet season, the incorporation of rice straw alone increased the uptake of P and K, similar to the crop supplied with additional inorganic fertilizer. Inorganic fertilizer treatments with or without additional chicken manure (CM) had higher grain and straw yields, yield components specifically number of tillers and panicles compared to CM and control treatments. The AEN of NSIC Rc212 was highest in plots with RIF, while CM produced the highest PEN due to higher percentage utilization or absorption of N in treatment with the least amount of N applied. Supplemental inorganic fertilizers in addition to rice residues and CM are indispensable to increase the rice yield. Incorporation of 4-5 t ha-1 rice straw for one cropping season of rice is not sufficient to significantly increase the N uptake and yield of the subsequent rice crop. The 2 month- fallow period after incorporation of straw and stubbles prior to transplanting did not affect rice yields suggesting that this length of time was sufficient to decompose the incorporated rice residues. The application of organic materials like rice straw and chicken manure was also instrumental in attaining adequate level of ROI. Therefore, continuous recycling and incorporation of rice straw in the soil during fallow period is not detrimental to the subsequent rice crop and contributes to the soil nutrient reserves which may lead to the improvement of yield and income in the long run.

Keywords : Fallow period, mowing, nutrient uptake, nitrogen-use efficiency, rice straw management

Annals of Tropical Research 34(2):1-25(2012)
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