981 resultados para SOIL MICROBIAL COMMUNITY
Resumo:
Aikuispotilaan kotisyntyisen keuhkokuumeen etiologinen diagnostiikka mikrobiologisilla pikamenetelmillä Tausta. Keuhkokuume on vakava sairaus, johon sairastuu Suomessa vuosittain n. 60 000 aikuista. Huolimatta siitä, että taudin hoito on kehittynyt, siihen liittyy yhä merkittävä, 6-15%:n kuolleisuus. Alahengitystieinfektion aiheuttajamikrobien tunnistaminen on myös edelleen haasteellista. Tavoitteet. Tämän työn tavoitteena oli tutkia Turun yliopistollisessa keskussairaalassa hoidettujen aikuispotilaiden keuhkokuumeen etiologiaa sekä selvittää uusien mikrobiologisten pikamenetelmi¬en hyödyllisyyttä taudinaiheuttajan toteamisessa. Aineisto. Osatöiden I ja III aineisto koostui 384 Turun yliopistollisen keskussairaalaan infektio-osastolla hoidetusta keuhkokuumepotilaasta. Osatyössä I tutkittiin keuhkokuumeen aiheuttaja¬mikrobeja käyttämällä perinteisten menetelmien lisäksi antigeeniosoitukseen ja PCR-tekniikkaan perustuvia pikamenetelmiä. Osatyö II käsitti 231 potilaasta koostuvan alaryhmän, jossa tutkittiin potilaiden nielun limanäytteestä rinovirusten ja enterovirusten esiintyvyyttä. Osatyössä III potilailta tutkittiin plasman C-reaktiivisen proteiinin (CRP) pitoisuus ensimmäisten viiden sairaalahoitopäi¬vän aikana. Laajoja tilastotieteellisiä analyysejä käyttämällä selvitettiin CRP:n käyttökelpoisuutta sairauden vaikeusasteen arvioinnissa ja komplikaatioiden kehittymisen ennustamisessa. Osatyössä IV 68 keuhkokuumepotilaan sairaalaan tulovaiheessa otetuista näytteistä määritettiin neutrofiilien pintareseptorien ekspressio. Osatyössä V analysoitiin sisätautien vuodeosastoilla vuosina 1996-2000 keuhkokuumepotilaille tehtyjen keuhkohuuhtelunäytteiden laboratoriotutkimustulokset. Tulokset. Keuhkokuumeen aiheuttaja löytyi 209 potilaalta, aiheuttajamikrobeja löydettiin kaikkiaan 230. Näistä aiheuttajista 135 (58.7%) löydettiin antigeenin osoituksella tai PCR-menetelmillä. Suu¬rin osa, 95 (70.4%), todettiin pelkästään kyseisillä pikamenetelmillä. Respiratorinen virus todettiin antigeeniosoituksella 11.1% keuhkokuumepotilaalla. Eniten respiratorisia viruksia löytyi vakavaa keuhkokuumetta sairastavilta potilailta (20.3%). 231 keuhkokuumepotilaan alaryhmässä todettiin PCR-menetelmällä picornavirus 19 (8.2%) potilaalla. Respiratorinen virus löytyi tässä potilasryh¬mässä kaiken kaikkiaan 47 (20%) potilaalta. Näistä 17:llä (36%) löytyi samanaikaisesti bakteerin aiheuttama infektio. CRP-tasot olivat sairaalaan tulovaiheessa merkitsevästi korkeammat vakavaa keuhkokuumetta (PSI-luokat III-V) sairastavilla potilailla kuin lievää keuhkokuumetta (PSI-luokat I-II) sairastavilla potilailla (p <0.001). Yli 100 mg/l oleva CRP-taso neljän päivän kuluttua sairaa¬laan tulosta ennusti keuhkokuumeen komplikaatiota tai huonoa hoitovastetta. Neutrofiilien komple¬menttireseptorin ekspressio oli pneumokokin aiheuttamaa keuhkokuumetta sairastavilla merkitse¬västi korkeampi kuin influenssan aiheuttamaa keuhkokuumetta sairastavilla. BAL-näytteistä vain yhdessä 71:stä (1.3%) todettiin diagnostinen bakteerikasvu kvantitatiivisessa viljelyssä. Uusilla menetelmilläkin keuhkokuumeen aiheuttaja löytyi vain 9.8% BAL-näytteistä. Päätelmät. Uusilla antigeeniosoitus- ja PCR-menetelmillä keuhkokuumeen etiologia voidaan saada selvitettyä nopeasti. Lisäksi näitä menetelmiä käyttämällä taudin aiheuttajamikrobi löytyi huomattavasti suuremmalta osalta potilaista kuin pelkästään tavanomaisia menetelmiä käyttämällä. Pikamenetelmien hyödyllisyys vaihteli taudin vaikeusasteen mukaan. Respiratorinen virus löytyi huomattavan usein keuhkokuumetta sairastavilta potilailta, ja näiden potilaiden taudinkuva oli usein vaikea. Tulovaiheen korkeaa CRP-tasoa voidaan käyttää lisäkeinona arvioitaessa keuhkokuumeen vaikeutta. CRP on erityisen hyödyllinen arvioitaessa hoitovastetta ja riskiä komplikaatioiden ke¬hittymiseen. Neutrofiilien komplementtireseptorin ekspression tutkiminen näyttää lupaavalta pi¬kamenetelmältä erottamaan bakteerien ja virusten aiheuttamat taudit toisistaan. Antimikrobihoitoa saavilla potilailla BAL-tutkimuksen löydökset olivat vähäiset ja vaikuttivat hoitoon vain harvoin.
Resumo:
Temporal (monthly in three fields for 12 months) and spatial (once in 23 fields during March-April) samplings were conducted in the major soybean (Glycine max)-growing region of the Brazilian Federal District. Fifty-three nematode genera were found in both samplings, but 13 were detected only by the temporal sampling, and one only by the spatial sampling. Fifty-three percent were plant-parasites, 35% were bacterivores, and about 12% were fungivores, predators and omnivores constituted the community that was dominated by the genera Helicotylenchus (40% of total abundance), Acrobeles (15%), Cephalobus (7.6%), Meloidogyne(5.6%) and Pratylenchus (4.9%). Heterodera glycines was not found in this study. There were no differences in ten ecological measurements [Ds, H', Es, T, FF/BF, (FF+BF)/PP, MI, PPI, mMI, and Dorylaimida (%)] between the two sampling types, but differences in indexes d and J'. Plant parasite populations dropped at the end of the crop cycle, remained at low levels during the dry season and the seedling period, then increased again in the crop-growing season. Fungivores maintained their low populations throughout the year, increasing only in June and July, the post-harvest period, when soil fungi decomposed root tissue. The population of bacterivores slightly declined during the dry season and the initial rainy season, but peaked in the middle of the rainy season, apparently associated with soil humidity. In the five most abundant nematodes, those of Acrobeles and Pratylenchus were more populous in wet soils, Cephalobus and Meloidogyne adapted well in dry soils, but Helicotylenchus survived abundantly in a wide range of soil moisture.
Resumo:
Diseases induced by Rhizoctonia solani, like damping-off and root and stem rot on soybean (Glycine max), are a serious problem around the world. The addition of some organic material to soil is an alternative control for these diseases. In this study, benzaldehyde and dried powders of kudzu (Pueraria lobata), velvetbean or mucuna (Mucuna deeringiana), and pine bark (Pinus spp.) were used in an attempt to improve soybean plant growth and to reduce the disease R. solani (AG-4) causes on soybean. Benzaldehyde (0.1-0.4 mL/kg of soil) and velvetbean (25-100 g/kg) significantly (P < 0.05) reduced mycelial growth of R. solani in laboratory tests. In greenhouse experiments, the percentage of non-diseased plants was higher in treatments with pine bark and velvetbean (50-100 g/kg). In soil treated with kudzu (r²=0.91) or velvetbean (r²=0.94), increasing rates of these amendments tended to increase plant fresh mass. In microplot field conditions, soil amended with velvetbean (r²=0.85) and pine-bark (r²=0.61) significantly reduced disease on soybean. Numbers of Bacillus megaterium (r²=0.87) and Trichoderma hamatum (r²=0.92) and hydrolysis of fluorescein diacetate (r²=0.91) were higher in soil amended with increasing rates of velvetbean, indicating an increase in microbial activity. From this study it is concluded that dried powders of velvetbean and pine bark added to soil can reduce Rhizoctonia-induced disease on soybean.
Resumo:
The overall purpose of this thesis was to increase the knowledge on the biogeochemistry of rural acid sulphate (AS) soil environments and urban forest ecosystems near small towns in Western Finland. In addition, the potential causal relationship between the distribution of AS soils and geographical occurence of multiple sclerosis (MS) disease was assessed based on a review of existing literature and data. Acid sulphate soils, which occupy an area of approximately 17–24 million hectare worldwide, are regarded as the nastiest soils in the world. Independent of the geographical locality of these soils, they pose a great threat to their surrounding environment if disturbed. The abundant metal-rich acid drainage from Finnish AS soils, which is a result of sulphide oxidation due to artificial farmland drainage, has significant but spatially and temporally variable ecotoxicological impacts on biodiversity and community structure of fish, benthic invertebrates and macrophytes. This has resulted in mass fish kills and even eradication of sensitive fish species in affected waters. Moreover, previous investigations demonstrated significantly enriched concentrations of Co, Ni, Mn and Al, metals which are abundantly mobilised in AS soils, in agricultural crops (timothy grass and oats) and approximately 50 times higher concentrations of Al in cow milk originating from AS soils in Western Finland. Nevertheless, the results presented here demonstrate, in general, relatively moderate metal concentrations in oats and cabbage grown on AS soils in Western Finland, although some of the studied fields showed anomalous values of metals (e.g. Co and Ni) in both the soil and target plants (especially oats), similar to that of the previous investigations. The results indicated that the concentrations of Co, Ni, Mn and Zn in oats and Co and Zn in cabbage were governed by soil geochemistry as these metals were correlated with corresponding concentrations extracted from the soil by NH4Ac-EDTA and NH4Ac, respectively. The concentrations of Cu and Fe in oats and cabbage were uncorrelated to that of the easily soluble concentrations in the soils, suggesting that biological processes (e.g. plant-root processes) overshadow geochemical variation. The concentrations of K and Mg in cabbage, which showed a low spread and were strongly correlated to the NH4Ac extractable contents in the soil, were governed by both the bioavailable fractions in the topsoil and plant-uptake mechanisms. The plant´s ability to regulate its uptake of Ca and P (e.g. through root exudates) seemed to be more important than the influence of soil geochemistry. The distribution of P, K, Ca, Mg, Mn and S within humus, moss and needles in and around small towns was to a high degree controlled by biological cycling, which was indicated by the low correlation coefficients for P, K, Ca, Mg and S between humus and moss, and the low spread of these nutrients in moss and needles. The concentration variations of elements in till are mainly due to natural processes (e.g. intrusions, weathering, mineralogical variations in the bedrock). There was a strong spatial pattern for B in humus, moss and needles, which was suggested to be associated with anthropogenic emissions from nearby town centres. Geogenic dust affected the spatial distribution of Fe and Cr in moss, while natural processes governed the Fe anomaly found in the needles. The spatial accumulation patterns of Zn, Cd, Cu, Ni and Pb in humus and moss were strong and diverse, and related to current industry, the former steel industry, coal combustion, and natural geochemical processes. An intriguing Cu anomaly was found in moss. Since it was located close to a main railway line and because the railway line´s electric cables are made of Cu, it was suggested that the reason for the Cu anomaly is corrosion of these cables. In Western Finland, where AS soils are particularly abundant and enrich the metal concentrations of stream waters, cow milk and to some extent crops, an environmental risk assessment would be motivated to elucidate if the metal dispersion affect human health. Within this context, a topic of concern is the distribution of multiple sclerosis as high MS prevalence rates are found in the main area of AS soils. Regionally, the AS soil type in the Seinäjoki area has been demonstrated to be very severe in terms of metal leaching, this area also shows one of the highest MS rates reported worldwide. On a local scale, these severe AS soil types coincide well with the corresponding MS clustering along the Kyrönjoki River in Seinäjoki. There are reasons to suspect that these spatial correlations are causal, as multiple sclerosis has been suggested to result from a combination of genetic and environmental factors.
Resumo:
This study aimed at quantifying total organic carbon stocks and its pools in Acrisol under agroforestry systems with six (AFS6) and thirteen years old (AFS13), slash-and-burn agriculture (SBA) and savanna native forest (SNF) in northeastern Brazil. Soil samples were collected at 0-0.05 m, 0.05-0.10 m, 0.10-0.20 m and 0.20-0.40 m depths in the dry and rainy seasons to evaluate total organic carbon (TOC) stocks and labile carbon (LC), fulvic acid fraction (C-FAF), humic acid fraction (C-HAF), humin (C-HF) and microbial biomass carbon (Cmic) contents. Additionally, carbon management index (CMI) was determined. Higher TOC stocks (97.7 and 81.8 Mg ha-1 for the 0-0.40 m depth in the dry and rainy seasons, respectively) and LC, humic substances and Cmic contents were observed in the AFS13 in all the depths. CMI also was higher in the AFS13 (0-0. 05 m: 158 and 86; 0.05-0.10 m: 171 and 67, respectively for the dry and rainy seasons) especially when compared to the SBA (0-0.05 m: 5.6 and 5.4; 0.05-0.10 m: 5.3 and 5.8, respectively for dry and rainy seasons). The agroforestry systems increased soil quality through the conservation of organic matter and can be considered an excellent strategy to assurance sustainability in tropical soil of Northeastern Brazil
Resumo:
This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock integrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where soil moisture and weight were standardized. Soil was kept near 70% moisture field capacity, being revolved every 20 days when all seedling emerged from soil were counted, identified and collected for dry mass assessment. The soil coverage by weeds, number of weed seedlings and dry mass of the weedy community were assessed. A phytoecological analysis was conducted. Weed composition is differentdifferent among management systems after 16 years. Areas with livestock showed much smaller number of weed species in comparison to systems where only grain crops are grown. The presence of livestock affects the potential of germination of soil seed bank. Agriculture systems are similar in terms of weed composition along soil profile, while systems involving livestock show little relation in what regards such sampled depths. Conservationist models of land exploration contribute to reduce severity of weed species occurrence in the long term.
Resumo:
Soil properties can influence weed community composition and weed density agricultural area. Knowing this relationship would allow to choose the best strategy for the control of such plants. This study aimed to investigate the correlation between weed density and chemical and physical attributes of soil in three areas (UCO, USC, and UPA) for commercial sugarcane cultivation in Campos dos Goytacazes, RJ. Grids of 40 m x 40 m were established in the areas, and soil samples were collected at the intersection points for physical and chemical analysis and evaluation of the soil seed bank (SSB), followed by a phyto-sociological survey of the weeds present. Samples were collected during two periods: February/March and June/July, 2010. SSB presented the greatest number of species per vegetation evaluated in the two sampling periods. Clay content had a positive effect leading to greater weed density in all areas (UCO, USC and UPA) in at least one of the densities (0-10 and 10-20 cm). On the other hand, sand content, when significant, presented a negative correlation with plant density in all the SSB areas analyzed. The pH negatively influenced the density of the species found through the phyto-sociological survey at USC and UPA. Cyperus rotundus, dominant in all areas, correlated positively with phosphorus, potassium, and clay content and negatively with pH and high sand content.
Resumo:
Accelerated herbicide degradation consists in its faster degradation in areas where it has been previously applied, due to the adaptation of microbial population to that particular compound. Accelerated degradation can reduce herbicide persistence and reduce its efficacy in soil. The objective of this study was to investigate if imidazolinone herbicides have enhanced microbial degradation in rice paddy soils. A laboratory experiment was conducted, evaluating the CO2 evolution rate from soils with and without history of herbicide application (imazapyr + imazapic and imazethapyr + imazapic), incubated with imidazolinone herbicides: imazethapyr, imazapyr, imazapic, imazamethabenz, imazamox and an untreated check. The amount of CO2 released from the soil was measured. As a result, the prior application of imidazolinones does not stimulate microbial degradation of herbicides from the same chemical group.
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Vegetation on rock outcrops in the "Chapada Diamantina" (soil islands) is often aggregated and surrounded by nude rock surfaces, thus creating natural units with well defined limits. The flowering and fruiting cycles of plants on 58 soil islands at altitudes between 1,100 and 1,140 meters above sea leavel were analyzed at Mãe Inácia Peak (12°27' S and 41°28' W) in the "Chapada Diamantina", Bahia, Brazil. The presence/absence of flowering and fruiting species on each soil island, and their respective cover areas were analyzed at both the population and community levels, and the phenophases of flowering and fruiting were observed during 24 successive months. The analyses of pollination and seed dispersal syndromes indicated that animals are more important in pollination than in seed dispersal (which is predominantly by anemochory and autochory). The flowering and fruiting of plants with animal pollination syndromes were correlated with rainfall and temperature. The flowering season varied during the year according to the pollination syndrome involved: entomophily was predominant from summer through autumn, ornithophily was predominant during winter, and anemophily in the spring. The staggered timing of flowering and fruiting among different species provides a nearly continuous supply of resources for the local fauna.
Resumo:
The objective of this study was to analyze the floristic composition and structure of the tree component in a seasonally deciduous forest on limestone outcrops, located in the northeast region of Goiás State, Brazil. A sample composed of 25 randomly sampled plots of 20 x 20 m (400 m²) within a 50 ha forest, was measured. All woody individuals > 5 cm diameter at breast height (DBH) had their diameter and height measured. The tree community was composed of 39 species with a density of 734 individuals ha-1; the richest families were Leguminosae (11 species), Bignoniaceae (4 species) and Apocynaceae (4 species). The forest had a basal area of 16.37 m² ha-1, with the most important species Cavanillesia arborea (3.26 m² ha-1), Pseudobombax tomentosum (2.35 m² ha-1), Dilodendron bipinnatum (1.84 m² ha-1), Tabebuia impetiginosa (1.36 m² ha-1) and Myracrodruon urundeuva (1.26 m² ha-1) occupying 61.5% of the total basal area of the forest. Several species grew on rocks, or in rock fissures or in places with a shallow layer of soil or even in litter over rocky layers. The floristic composition showed links with the "Caatinga" flora, with other patches of seasonal forests in Central Brazil and in the Pantanal, and with the Chiquitano forests of Bolivia too, containing even two species considered as endemic to the "Caatinga".
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The Baltic Sea is unique by its biological, geochemical and physical features. The number of species of larger organisms is small and the species composition is distinctive. On the contrary microbial communities are diverse. Because of the low salinity levels, bacterial communities differ from the ones in the oceans. Knowing the structure of these communities better and how they response to different environmental conditions helps us to estimate how different factors affect the balance and function of the Baltic Sea ecosystem. Bacteria are the key players when it comes to natural biogeochemical processes and human-induced phenomena like eutrophication, oil spills or disposal of other harmful substances to the sea ecosystem. In this thesis, bacterial community structure in the sea surface microlayer and subsurface water of the Archipelago Sea were compared. In addition, the effect of diatom derived polyunsaturated aldehydes on bacterial community structure was studied by a mesocosm experiment. Diesel, crude oil and polycyclic aromatic hydrocarbon degradation capacity of the Baltic Sea bacteria was studied in smaller scale microcosm experiments. In diesel oil experiments bacteria from water phase of the Archipelago Sea was studied. Sediment and iron manganese concretions collected from the Gulf of Finland were used in the crude oil and polycyclic aromatic hydrocarbon experiments. The amount of polycyclic aromatic hydrocarbon degradation genes was measured in all of the oil degradation experiments. The results show how differences in bacterial community structure can be seen in the sea surface when compared to the subsurface waters. The mesocosm experiment demonstrated how diatom-bacteria interactions depend on other factors than diatom derived polyunsaturated aldehydes, which do not seem to have an effect on the bacterial community structure as has been suggested in earlier studies. The dominant bacterial groups in the diesel microcosms differed in samples taken from a pristine site when compared to a site with previous oil exposure in the Archipelago Sea area. Results of the study with sediment and iron-manganese concretions indicate that there are diverse bacterial communities, typical to each bottom type, inhabiting the bottoms of the Gulf of Finland capable to degrade oil and polycyclic aromatic hydrocarbon compounds.
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Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire bacterial communities in the environment. In the present study, we have used this approach to assess the bacterial community in the rhizosphere soil of sugarcane at different times and under different nitrogen fertilization conditions. At the high taxonomic level, few differences between samples were observed, with the phylum Proteobacteria (29.6%) predominating, followed by Acidobacteria (23.4%), Bacteroidetes (12.1%), Firmicutes (10.2%), and Actinobacteria (5.6%). The exception was the Verrucomicrobia phylum whose prevalence in N-fertilized soils was approximately 0.7% and increased to 5.2% in the non-fertilized soil, suggesting that this group may be an indicator of nitrogen availability in soils. However, at low taxonomic levels a higher diversity was found associated with plants receiving nitrogen fertilizer. Bacillus was the most predominant genus, accounting for 19.7% of all genera observed. Classically reported nitrogen-fixing and/or plant growth-promoting bacterial genera, such as Azospirillum, Rhizobium, Mesorhizobium, Bradyrhizobium, and Burkholderia were also found although at a lower prevalence.
Resumo:
This research aimed to determine the soil seed bank and its relationship with environmental factors that have an influence in the distribution of the vegetation above the ground in an excluded area of natural grassland in the South of Brazil. Most of the 122 identified species in the seed bank were perennials. Data analysis indicated three distinct community groups, according to the size and composition of the soil seed bank in lowlands with permanent wet soils, in lowlands and in other areas. In general, lowlands were characterized by low-fertility soils, high moisture and aluminum contents, being spatially homogeneous habitats and, therefore, more restricted to vegetation heterogeneity than other parts of the relief. Environmental factors most associated with soil seed bank size and composition were relief position and their co-related soil variables such as: soil moisture content, potassium content, organic matter, basic saturation of cation exchange soil capacity, exchangeable basics sum of the soil and clay soil content. According to that, relief position, associated with combined effects of soil chemical properties related to it, determines the observed variation pattern of the soil seed bank, as a reflection of the vegetation above the area.
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Background: Soil-transmitted helminth (STH) infections are endemic in Honduras and efforts are underway to decrease their transmission. However, current evidence is lacking in regards to their prevalence, intensity and their impact on children’s health. Objectives: To evaluate the prevalence and intensity of STH infections and their association with nutritional status in a sample of Honduran children. Methodology: A cross-sectional study was done among school-age children residing in rural communities in Honduras, in 2011. Demographic data was obtained, hemoglobin and protein concentrations were determined in blood samples and STH infections investigated in single-stool samples by Kato-Katz. Anthropometric measurements were taken to calculate heightfor- age (HAZ), BMI-for-age (BAZ) and weight-for-age (WAZ) to determine stunting, thinness and underweight, respectively. Results: Among 320 children studied (48% girls, aged 7–14 years, mean 9.7661.4) an overall STH prevalence of 72.5% was found. Children .10 years of age were generally more infected than 7–10 year-olds (p = 0.015). Prevalence was 30%, 67% and 16% for Ascaris, Trichuris and hookworms, respectively. Moderate-to-heavy infections as well as polyparasitism were common among the infected children (36% and 44%, respectively). Polyparasitism was four times more likely to occur in children attending schools with absent or annual deworming schedules than in pupils attending schools deworming twice a year (p,0.001). Stunting was observed in 5.6% of children and it was associated with increasing age. Also, 2.2% of studied children were thin, 1.3% underweight and 2.2% had anemia. Moderate-to-heavy infections and polyparasitism were significantly associated with decreased values in WAZ and marginally associated with decreased values in HAZ. Conclusions: STH infections remain a public health concern in Honduras and despite current efforts were highly prevalent in the studied community. The role of multiparasite STH infections in undermining children’s nutritional status warrants more research.
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The diversity and load of heterotrophic bacteria and fungi associated with the mangrove soil from Suva, Fiji Islands, was determined by using the plate count method. The ability of the bacterial isolates to produce various hydrolytic enzymes such as amylase, gelatinase and lipase were determined using the plate assay. The heterotrophic bacterial load was considerably higher than the fungal load. There was a predominance of the gram positive genus, Bacillus. Other genera encountered included Staphylococcus, Micrococcus, Listeria and Vibrio. Their effectiveness on the degradation of commercial polythene carry bags made of high density polyethylene (HDPE) and low density polyethylene (LDPE) was studied over a period of eight weeks in the laboratory. Biodegradation was measured in terms of mean weight loss, which was nearly 5 % after a period of eight weeks. There was a significant increase in the bacterial load of the soil attached to class 2 (HDPE) polythene. After eight weeks of submergence in mangrove soil, soil attached to class 1 and class 3 polythene mostly had Bacillus (Staphylococcus predominated in class 2 polythene). While most of the isolates were capable of producing hydrolytic enzymes such as amylase and gelatinase, lipolytic activity was low. Class 2 HDPE suffered the greatest biodegradation.