Characterization of lignocellulolytic bacterial strains associated with decomposing wood residues in the Lagos lagoon, Nigeria

Aims: The presence of lignocelluloses, especially sawdust in the Lagos lagoon and the attendant ecological problems warranted studies on their degradation. This study aimed to isolate and identify the indigenous bacterial strains capable of utilizing lignocellulosic wastes under the prevalent tropical estuarine conditions. Methodology and results: Nine bacterial species were obtained by elective culture from decomposing wood residues in the lagoon. They were identified on the basis of morphology, biochemical characteristics and analysis of their 16S rRNA gene sequences as Streptomyces, Bacillus and Paenibacillus species. They were cultured on various ligninrelated lignocellulosic substrates over a period of 7 to 12 days. All the isolates showed moderate to very good growth on sugarcane baggase. Streptomyces albogriseolus strain AOB and Paenibacillus sp. ROB showed good growth on grass while on sawdust, only Streptomyces AOB, and Bacillus megaterium strain NOB showed good growth. High performance liquid chromatographic analysis showed that the Streptomyces species completely utilized coniferyl alcohol, B. megaterium strain NOB utilized 90-100% of all the lignin- related aromatic compounds. All the bacterial species utilized less than 40% of sinapyl alcohol, Bacillus sp. OOB and Paenibacillus sp. strain ROB failed to utilize vanillic acid. Conclusion, significance and impact of study: The isolates degraded lignocellulosic wastes and lignin-related compounds. The role of fungi in the breakdown of lignocellulose in the Lagos lagoon had been the subject of previous research considerations whilst the role of bacteria spp was unreported. Autochthonous bacterial species may equally play a role in the bio-rehabilitation of the sawdust-polluted water of the Lagos lagoon

Kraft lignin degradation by autochtonous streptomyces strains isolated from a tropical lagoon ecosystem

Kraft lignin contributes to the toxicity of the pulping plant effluent and is known to resist microbial treatment.The lignin component must be removed from lignocellulose biomass to enhance the release of fermentable sugars for the production of biofuel and other value-added end products. Lignin-degrading bacteria provide an advantage due to their ease of isolation,wider tolerance of environmental conditions and genetic manipulations compared with their fungal counterparts. There is no documented evidence on the degradation of kraft lignin by bacteria in the tropical estuarine ecological niche in Nigeria. Bacterial growth and assessment of kraft-lignin degradation in submerged fermentation was carried out for a period of 10 days using Streptomyces spp isolated from a tropical lagoon as the inocula. The organisms utilized 23 to 99 % kraft-lignin at the rate of 2.3×10-5 to 9.9×10-5 g.d-1cm-3 with specific growth rates of 0.020 - 0.084 h-1and doubling times of 8.3 - 35.1 h. Maximum values obtained for laccase and peroxidase activities were 9.5x10-2 and 400 μ mol mg -1min -1 respectively. The aim of this study was to obtain evidences for Kraft lignin degradation by indigenous tropical estuarine Streptomyces species from Lagos, Nigeria. The Autochthonous bacterial species of the Lagos lagoon utilize kraft lignin as a sole carbon source and may be good candidates for biotechnological purposes. The outcome of this study has bridged an information gap in the tropical environment and will complement existing global data because the information on the degradation of kraft lignin by marine Streptomyces is not common

Pectinase production by Bacillus megaterium, Bacillus bataviensis, and Paenibacillus sp. isolated from decomposing wood residues in the Lagos lagoon

Three wood decomposing bacteria isolated from the Lagos lagoon, Bacillus megaterium, Bacillus bataviensis and Paenibacillus sp. were screened for their pectinase producing abilities using pectin as substrate under submerged fermentation (SMF) conditions. The results showed that all three isolates produced appreciable pectinolytic activities. Paenibacillus sp. showed the highest pectinase activity when compared with the other two isolates. The optimum pH for pectinase activity for both B. megaterium and B. bataviensis was 8.0 while it was 6.5 for Paenibacillus sp., B. bataviensis, and B. megaterium showed optimum pectinase activity at 60°C and Paenibacillus sp. at 40°C. Metal ions such as Na+ and K+ improved the activity of pectinase produced by the three isolates when compared to the effect of Zn2+ and Mn2+. The molecular weights of the enzymes were also estimated by gel filtration as 29,512 da, 32,359 da, and 25,119 da for Paenibacillus sp., B. megaterium and B. bataviensis respectively. The study has provided a platform for further investigation into the biochemical characterization of the enzyme, and optimization of culture conditions to scale up pectinase production for commercial exploitation

The degradation of coniferyl alcohol and the complementary production of chlorogenic acids in the growth culture of Streptomyces albogriseolus KF977548 isolated from decaying wood residues

Coniferyl alcohol is one of the major precursors of lignin; the most abundant aromatic compound and a natural resource currently receiving attention because of the value-added metabolites resulting from its degradation. Growth study of Streptomyces albogriseolus KF977548 (strain AOB) isolated from decaying wood residues in a tropical estuarine ecosystem was carried out using coniferyl alcohol as a sole carbon source. Cell growth and metabolite production were monitored at 24 h interval by dry weight measurements and HPLC, LC–MS-DAD analyses. Biochemical and PCR assays were carried out to detect the major catabolic enzymes of interest. Strain AOB utilized coniferyl alcohol completely within 72 h ( = 0.204 h−1, Td = 3.4 h). Laccase and peroxidase were released into the growth medium up to 0.099 and 98 mol/mL respectively. Protocatechuate 3, 4-dioxygenase and demethylase were detected in the genome whilst ortho-adipate pathway was clearly indicated. Growth on coniferyl alcohol or caffeic acid as mono substrates resulted in the production of secondary metabolites identified by HPLC–MS as 1- caffeoylquinic and 3,4,5-tricaffeoylquinic acids, known as chlorogenic acids, in the culture medium. The microbial production of chlorogenic acids from a lignin-related substrate base by strain AOB could arouse a plausible biotechnological process

Efficacy of intervention strategies for bioremediation of crude oil in polluted soil microcosm

Crude oil, though not manmade but largely manipulated by man to provide different oil-based products has become a major source of environmental pollution. This menace on land do contribute to the retardation of vegetation growth and human health hazards, while in water it may be toxic to aquatic animals. The search for the solution to ameliorate the seemingly unending pollution and its side effects necessitated the evaluation on the effect of bioaugmentation, biostimulation and natural attenuation of crude oil pollution in soil microcosms. The bacterial species selected for this study (Bacillus thuringensis strain LG32 and Burkolderia pseudomallei strain A81) were preliminarily identified using the conventional biochemical tests and further identification was carried out using the API kit. The results of the study carried out over a period of five weeks indicated that there was a marked reduction in the available phosphorous and potassium in the bioaugmented and biostimulated soils compared with that of the control. The mean values for total viable counts (TVC) of population of hydrocarbon utilizing bacteria (HUB) was higher in the bioaugmented soil ranged (LG32=6.0-7.5log10cfu g-1 ; A81=5.5- 7.5log10cfug-1 ; LG32+A81=6.0-7.5log10cfug-1 ) compared with that of the control (6.0-6.2log10cfug-1 ). When bioaugmentation was combined with biostimulation, the soil had higher counts of HUB (6.0-9.0log10cfug-1 ) and HUF (3.5-6.5log10cfug-1) compared to bioaugmentation without stimulation (HUB: 6.0-7.5; HUF: 3.5-5.5). The GC result indicated that by day 35, 96.92% of the aliphatic and aromatic components have been degraded in the augmented soil, higher than the natural attenuation control

Potentials of microorganisms associated with plantain peels in the Lagos metropolis for biodegradation and bioconversion.

The role of microbes in the degradation of plantain derived-wastes and their potential to produce cellulolytic enzymes was assessed. Soil samples of decomposing waste piles were collected from two major plantain markets in the Lagos metropolis and analyzed for physicochemical properties, toxic heavy metal content and microbial populations. Findings revealed that the values of moisture content of the two soils varied between 7.27±0.04 and 8.06±0.19 %. M-12 site had the highest organic matter content of 6.89±0.14 %. A similar pattern was observed for nitrate, phosphate and chloride levels while some heavy metals were also detected in varying and high amounts. The highest viable bacterial counts was 58.0±2.9 x 104 cfu/g at MU and there were no fungi at the site whereas M-12 had a fungal count of 40.0±3.3 x 103 cfu/g. Out of the total of 34 isolates encountered, 8 isolates having maximum cellulase activities were selected for further studies by the primary screening technique. These test organisms were then evaluated by secondary screening for enzyme production. The test organisms were phenotypically and biochemically characterized and identified as Klebsiella pneumoniae spp pneumoniae (2 strains), Klebsiella pneumoniae spp ozaenae, Enterobacter aerogenes, Providencia alcalifaciens, Aspergillus flavus, Aspergillus fumigatus and Aspergillus niger respectively. Both the bacteria and moulds were found to be capable of utilizing lignin and cellulosic substrates for growth and for production of cellulolytic enzymes. It is suggested that such microorganisms could be useful in bioconversion of cellulosic substrates like plantain-derived wastes for biotechnological application

Assessment of bacterial degradation of lignocellulosic residues (sawdust) in a tropical estuarine microcosm using improvised floating raft equipment

In situ and laboratory studies were carried out to determine the ability of bacterial strains isolated from a tropical lagoon to degrade lignin and carbohydrate components of sawdust, with a view to abating the impact of sawdust pollution on these ecosystem. A floating raft system was designed and fabricated to carry out the in situ biodegradation studies over a period of 24 weeks. Nine bacterial strains identified by 16S rRNA gene sequencing as species of Streptomyces, Bacillus and Paenibacillus isolated from the lagoon were used as seed organisms. In the in situ study, 59.2% of sawdust was depleted at the rate of 1.175 x 10-4 gd-1 cm-3 by the bacterial isolates, whereas the lignin component of the sawdust decreased by up to 82.5% at the rate of 1.80 x 10-5 gd-1 cm-3. The maximum decrease in carbohydrate content was 85% at the rate of 2.192 x 10-7 gd-1 cm-3. In a similar experiment under laboratory conditions, total weight losses ranging from 26 to 51% in the wood residues were observed

Pectinase Production by Bacillus and Paenibacillus SP. Isolated From Decomposing Wood Residues in the Lagos Lagoon

Three wood decomposing bacteria isolated from the Lagos lagoon, Bacillus megaterium, Bacillus bataviensis and Paenibacillus sp. were screened for their pectinase producing abilities using pectin as substrate under submerged fermentation (SMF) conditions. The results showed that all three isolates produced appreciable pectinolytic activities. Paenibacillus sp. showed the highest pectinase activity when compared with the other two isolates. The optimum pH for pectinase activity for both B. megaterium and B. bataviensis was 8.0 while it was 6.5 for Paenibacillus sp., B. bataviensis, and B. megaterium showed optimum pectinase activity at 60°C and Paenibacillus sp. at 40°C. Metal ions such as Na+ and K+ improved the activity of pectinase produced by the three isolates when compared to the effect of Zn2+ and Mn2+. The molecular weights of the enzymes were also estimated by gel filtration as 29,512 da, 32,359 da, and 25,119 da for Paenibacillus sp., B. megaterium and B. bataviensis respectively. The study has provided a platform for further investigation into the biochemical characterization of the enzyme, and optimization of culture conditions to scale up pectinase production for commercial exploitation

Antimicrobial activities of the Streptomyces ceolicolor strain AOB KF977550 isolated from a tropical estuary

The aim of this study was to screen for important antibiotic producing species of the genus Streptomyces from a tropical estuary. Five bacterial strains were isolated from the Lagos lagoon and identified by 16S rDNA gene sequencing as Streptomyces albogriseolus, S. aureus, S. coelicolor, S. albus, and S. pseudogriseolus. Ethyl acetate extracts of Streptomyces spp. fermented broths were evaluated against laboratory strains of MRSA Methicillin-resistant Staphyloccus aureus (MRSA) 144 m, Bacillus coagulans UL001, and Escherichia coli as well as the standard strains Klebsiella pneumonia ATCC 8308, Gardnerella vaginalis ATCC 27853 and Salmonella typhi ATCC 13311 using the well diffusion method. The presence of secondary metabolites was determined and analysed using gas chromatography-mass spectrometry (GC-MS). A broad spectrum of activity was only observed for S. coelicolor on all of the tested bacteria except S. typhi, ant GC-MS analysis revealed the presence of 16 secondary metabolites with relevant antibiotic properties. The result of this study suggest that Lagos Lagoon is a potential source and reservoir of novel antibiotics. Keywords: Streptomyces, Antibiotics, Resistance, Secondary Metabolite