Aim: To isolate and characterize lactic acid bacteria (LAB) and determine whether they could potentially be used as heavy metal (cadmium and lead) absorbing probiotics. Methods and Results: The study ...used 53 environmental (mud and sludge) samples to isolate cadmium‐ and lead‐resistant LAB, by following spared plate technique. A total of 255 cadmium‐ and lead‐resistant LAB were isolated from these samples. The survival of 26 of the LAB was found after passing through sequential probiotic characterizations. These 26 probiotic LAB exhibited remarkable variations in their metal‐resistant and metal‐removal abilities. Of 26, seven (Cd54‐2, Cd61‐7, Cd69‐12, Cd70‐13, Pb82‐8, Pb96‐19 and Cd109‐16) and four (Pb71‐1, Pb73‐2, Pb85‐9 and Pb96‐19) strains displayed relatively elevated cadmium‐ and lead‐removal efficiencies from water, respectively, compare with that of the remaining strains. Strains Cd70‐13 and Pb71‐1 showed the highest cadmium (25%) and lead (59%) removal capacity from MRS (De Man, Rogosa and Sharpe) culture medium, respectively, amongst the selected strains and showed a good adhesive ability on fish mucus. A phylogenetic analysis of their 16S rDNA sequences revealed that the strains Cd70‐13 and Pb71‐1 belong to Lactobacillus reuteri. Conclusion: Excellent probiotic, metal sorption and adhesive characteristics of newly identified Lact. reuteri strains Cd70‐13 and Pb71‐1 were isolated, which indicated their high potential abilities to survive in the intestinal milieu and to uptake the tested metals from the environment. Significance and Impact of the Study: To our knowledge, this is the first study that has aimed to isolate, characterize and identify metal‐resistant LAB strains that have potential to be a probiotic candidate for food and in vivo challenge studies in the intestinal milieu of fish for the uptake and control of heavy metal bioaccumulation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The present study attempted to identify the efficient hazardous metal-removing sorbent from specific types of soil, upper and middle layer shirasu, shell fossil, tuff, akadama and kanuma soils of ...Japan by physico-chemical and metal (arsenic, cadmium and lead) removal characterizations. The physico-chemical characteristics of soil were evaluated using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy techniques, whereas metal removal properties of soil were characterized by analyzing removal capacity and sorption kinetics of potential metal-removing soils. The chemical characteristics revealed that all soils are prevalently constituted of silicon dioxide (21.83–78.58 %), aluminum oxide (4.13–38 %) and ferrous oxide (0.835–7.7 %), whereas calcium oxide showed the highest percentage (65.36 %) followed by silicon dioxide (21.83 %) in tuff soil. The results demonstrated that arsenic removal efficiency was higher in elevated aluminum oxide-containing akadama (0.00452 mg/L/g/h) and kanuma (0.00225 mg/L/g/h) soils, whereas cadmium (0.00634 mg/L/g/h) and lead (0.00693 mg/L/g/h) removal efficiencies were maximum in elevated calcium oxide-containing tuff soil. Physico-chemical sorption and ion exchange processes are the metal removal mechanisms. The critical appraisal of three metal removal data also clearly revealed cadmium > lead > arsenic order of removal efficiency in different soils, except in tuff and akadama soils followed by lead > cadmium > arsenic. It clearly signified that each type of soil had a specific metal adsorption affinity which was regulated by the specific chemical composition. It may be concluded that akadama would be potential arsenic-removing and tuff would be efficient cadmium and lead-removing soil sorbents.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The purpose of the present study was to isolate and identify the metal-resistant lactic acid bacteria from sediments of coastal aquaculture habitats for removal of cadmium and lead from ambience. ...Collected sediment samples were used to isolate the cadmium- and lead-resistant bacterial colonies by spread plate technique using agar media (De Man, Rogosa and Sharpe) supplemented with cadmium or lead at 50 mg/l. Isolates were identified by bacterial colony polymerase chain reaction and sequencing of 16S ribosomal deoxyribonucleic acid. Metal removing probiotic was determined by characterizing the lactic acid yield in culture media, viability in fish intestine, metal-resistant and metal-removal efficiencies. 16S ribosomal deoxyribonucleic acid sequencing data of five (Cd10, Cd11, Pb9, Pb12 and Pb18) and other all isolates clearly showed 99 % similarities to
Enterococcus faecium
and
Bacillus cereus,
respectively. The Pb12 exhibited higher lactic acid yield (180 mmol) than that of the remaining
E. faecium
strains and excellent viability without pathogenicity; therefore, further study was carried out using Pb12 strain. The selected Pb12 strain showed elevated metal resistant (minimum inhibitory concentrations 120 and 800 mg/l for cadmium and lead, respectively) and removal efficiencies Cadmium 0.0377 mg/h/g and lead 0.0460 mg/h/g of cells (wet weight). From the viability and metal removal points of view, it can be concluded that isolated metal-resistant
E. faecium
Pb12 strains might be used as potential probiotic strains for removing heavy metals from fish intestinal milieu to control the progressive bioaccumulation of heavy metals in the fish.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Chironomid larvae (2.0
individuals/cm
2) were introduced in sediment–water microcosms of 3.0
l capacity to assess the impact of bioturbation on phosphorus flux across sediment–water interface, under ...different nutrient-enriched conditions. Recruitment of chironomid resulted in 21% and 19% increase in aquatic orthophosphate and nitrate quanta, respectively, with concomitant decrease in nutrient concentration in the sediment compared to macrofauna-free controls under mesotrophic condition. It implied that cost of fertilizer for biological production could be curtailed by at least 19–21% by recovering nutrients stored in the sediment pool. Bioturbation-induced orthophosphate flux under chironomid impacted mesotrophic treatment was 2.3- and 1.8-fold greater than that under bioturbated eutrophic treatment, suggesting that the macrofaunal impact was reduced in the presence of higher nutrient load perhaps due to physicochemical stressors under eutrophic condition. Nevertheless, chironomid larvae can further accelerate nutrient enrichment in the eutrophic system that may invite a “snow ball effect” towards a hypereutrophic one. The counts of both heterotrophic and phosphate solubilizing bacteria show strong positive correlation with orthophosphate concentration in water and the correlation also exists between organic carbon concentration in sediment and phosphate in overlying water. This implied that the accelerated phosphate flux was the result of coordinated eco-engineering activities of chironomid larvae and microbe-mediated mineralization of organic matter.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
An experiment was conducted using 15 glass aquariums to ascertain the pathways of removal of cadmium through numerical and compositional manipulation of ecosystem components and their role in Cd ...removal in different aquatic ecosystems. Each aquarium was provided with surface sediment @ 2
kg, filled with 15
L tap water and randomly distributed into five treatments having three replicates in each. Cadmium chloride (CdCl
2) of analytical grade was added @ 2
mg/L to the water of each aquarium and mixed gently. Except for the first one, the other four systems received unio (
Lamellidens marginalis, 55
±
2.5
g) @ 6
pieces/aquarium. Tilapia (
Oreochromis mossambicus, 35
±
3
g) was introduced @ 6
fish/aquarium in the third and fifth systems, whereas pistia
(Pistia stratiotes) was introduced @ 50
g/aquarium in the fourth and fifth systems for a 28-day observation period. The samples of water, sediment, unio, fish and pistia were collected from different systems at 7-day intervals and analyzed. Results revealed that mean substantial reduction of Cd in water varied between 1.820 and 1.994
mg/L in different simulated ecosystems. Ecosystem efficiency of Cd removal varied in the different ecosystems and showed highest (11%) value in the ecosystem carrying five components, which suggested a cumulative effect of increasing number of components employed in different simulated aquatic ecosystems significantly facilitated the reduction of the level of Cd concentration in water column. Pistia exerted (12.88–547.5 times) higher rate of Cd accumulation over the other components employed in five simulated ecosystems of various component structures. Therefore, in the present study, it may be concluded that ecosystems carrying five components exhibited the best performance for optimum minimization of Cd removal from water column. It can also be concluded that ecosystem components showed a variable performance and pistia was the efficient component from the perspective of Cd removal.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Advanced fry of common carp (1.6
±
0.2 g) were reared in experimental outdoor tanks (4500 l; 3
×
1.5
×
1 m) for 312 or 151 days under six stocking conditions of 8, 13, 16, 32, 48 and 64 fish per tank ...for ascertaining the threshold and critical levels of ammonium and, hence, to recommend the optimum stocking density of common carp for culture under rearing stage conditions. The samples of water were monitored from each tank at regular intervals for water quality parameters as well as for ammonium concentrations. Fishes were harvested at the end of the experiment. The results revealed a significant decrease in fish growth as stocking density increased. Absence of mortality and favorable growth resulted in maximum fish biomass at the stocking density of 16 fish/tank, but the heavy mortality and stunted growth caused the poor total fish biomass in the highest stocking density employed. The interactions between ammonium and fish growth were expressed at three different concentration levels of ammonium: (a) favorable concentration range (0.262–0.294 mg l
−
1
), (b) growth inhibiting concentration range (0.313–0.322 mg l
−
1
) and (c) lethal concentration range (0.323–0.422 mg l
−
1
). The ambient ammonium concentrations of 0.313 mg l
−
1
(or equivalent ammonia concentration of 0.0342 mg l
−
1
) and 0.323 mg l
−
1
(or equivalent ammonia concentration of 0.043 mg l
−
1
), observed for stocking density ranging from 17 to 19 fish per tank, were considered to be the threshold and critical levels of ammonium that caused growth inhibition and mortality of fish. Fish mortality was higher when the ratio of DO to ammonium remained quite low (<
15), but no mortality occurred with higher ratio. Considering the economic viability of the production system, this appears that the optimum fish stocking density would be around SD 16 (equivalent to 210 g m
−
3
).
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Wastewater nutrient dynamics is characterized by the enhanced activities of microbial enzyme complex resulting in the decomposition of domestic sewage and maintaining ecological resilience of a waste ...stabilization pond. This altered stress-induced bacterial metabolism has been studied for nutrient reclamation through bacterial multi-enzyme signature assessment (MESA) of domestic wastewater. Strong correlation between the protease activity (PA) and NH
4
-N (
r
= 0.918) and proteolytic bacteria (
r
= 0.990) at the inlet suggests a consistent protein degrading activity (2 U/ml) of high-protein load present in inflowing organic nitrogenous waste products indicating the predominance of ongoing ammonification process. Higher correlation between PO
4
-P and alkaline phosphatase activity (APA) at the inlet (
r
= 0.866) and outlet (
r
= 0.968) than the mid-site (
r
= 0.654) suggests substrate dependent but enzyme limited high phosphate uptake at inlet by biological integrity and PO
4
-P reclaimed favorable environment (PO
4
-P: 1 ± 0.02 mg/l) for bacterial growth at outlet. Higher cellulase activity (CA) being positively correlated with organic-C (
r
= 0.839) at the oxygen-deficient inlet site revealed efficient utilization of high organic-C load by both aerobic and facultative anaerobic cellulolytic bacteria and negative correlation between CA and BOD is due to aerobic organic matter degradation favored by grazing food chain dominated ecological integrity of mid-site and outlet. Enzyme signature index trend of APA > PA > CA clearly revealed higher nutrient and BOD–COD removal than carbon metabolism by the present system dynamics being influenced by a shifting dominance of substrate-induced to enzyme-induced bacterial metabolism from sewage inflow to outflow. Thus, MESA reveals the adaptation of wastewater grown nutrient cycling bacteria to luxuriant storage of nutrients in excess of their requirement mediated by their released enzymes responsible for wastewater reclamation and ecological resilience.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Water quality measurements can indicate carbon status or algal biomass. Microalgae have an excellent ability to utilize all forms of dissolved inorganic carbon at different pH conditions. ...Water quality signature (WQS) using three different expressions with (i) pH; (ii) total alkalinity, hardness and total dissolved solids; and (iii) nitrate and conductivity of water was assessed in 32 wetlands distributed across 5 districts of West Bengal, India. Two zones were clearly discernible: coldwater (15–23 °C) high-altitude lakes in Darjeeling, and tropical (31–32 °C) low-altitude wetlands. Multivariate analysis of the Akaike information criterion (ACI) model revealed location-specific variability of agro-climatic and biogeochemical interactions. Dissolved inorganic carbon and inorganic nitrogen appeared to be important in regulating the phytocarbon content of microalgae. The wetlands located in the Gangetic alluvial tropical or semi-coastal areas (Hooghly, 24-Parganas, Nadia, Midnapore) were alkaline (pH = 7.52–7.97) where half-bound carbon dioxide comprised the major component (18–26%) of total inorganic carbon, with moderate to eutrophic (PO4-P− 0.16–0.23 mg/l) states which have a negative feedback to global warming. The heterogeneity of measured water quality signature consolidated the sanative nature of wetlands for their complex functional attributes with agro-climatic, biogeochemical and soil-water-biological interactions.
Human urine is a potential source of various nutrients, minerals and trace elements. Its use as a fertilizer is growing popular among farmers. Here, we examined the pattern of changes in the counts ...of coliform, heterotrophic bacteria as well as physico-chemical characteristics of human urine during different days of storage under closed conditions at ambient temperature. We observed that after 253 days of storage under closed condition, the coliform counts were reduced significantly and remained within the safe limit to be used as fertilizer. With increase in storage period, the concentration of phosphate showed decline coupled with rise in pH, alkalinity and electrical conductance. Our study revealed that human urine can be used as safe fertilizer after 8 months of storage under closed conditions at ambient temperature ranging 25-35ºC.
Winter reduction of fish growth is one of the major concerns in aquaculture. Using the principle of greenhouse mediated raised temperature, the issue has been addressed by examining the growth ...responses of some tropical fishes in polyculture (rohu, mrigal, bata, Japanese punti, grass carp, common carp, magur, freshwater prawn) and two stocking ratios (80:20 and 20:80) with surface and column feeder (catla, silver carp, rohu, Japanese punti and bata) and bottom feeder (mrigal and common carp). Advanced fry of these fishes were introduced separately in solar heated greenhouse and in open polyhouse (13 × 1.5 × 2 m3) placed in triplicate in a pond and reared for 120 or 98 days during the winter for two consecutive years. The rate of survival (20–83%) and net weight gained by different species of fish were distinctly higher in closed set up (0.22–2.95 g/day) than in open (4–66%; 0.11–1.80 g/day) ones in both trials. Among the species, warmth induced net weight gain was maximal for Japanese punti (196 g), followed by rohu (159 g), mrigal (115 g), grass carp (104 g), bata (36 g) and freshwater prawn (28 g) in polyculture. The frequency distribution of harvested fishes was skewed towards large fishes in solar heated greenhouse and smaller ones in open units. Water temperature ranged from 21.6–28.1 °C and 17.2–23.7 °C in the closed and open units, whereas mean temperature remained 4.5–5 °C higher in the former than in latter. There was no marked differences in total alkalinity (219–231 mg/l), inorganic carbon (289–417 mg/l), organic carbon (4.27–4.52 mg/l), dissolved oxygen (6.61–6.75 mg/l), total dissolved solids (420.48–423.74 mg/l) and conductivity (549.83–563.29 μs/cm) between the closed and open enclosures, and remained within the range for fish culture. The score values of the sum total of the integrated ecological conditions revealed that ~ 5 °C rise in water temperature during winter enhanced as high as 36% increased yield of fish (2546 kg/ha) over open units mediated through microbial driven augmented manure mineralization leading to increased primary productivity, zooplankton abundance and ecological integrity. In essence, the solar heated greenhouse would be of considerable use for circumventing the retarded growth during winter in tropical fishes.
Display omitted
•Winter reduction of fish growth is one of the major concerns in aquaculture.•The concept of greenhouse was employed in impeding the winter growth and restored the normal annual fish yield of some tropical fishes.•About 5ºC rise of water temperature in the mimicked greenhouse was capable of preventing winter reduction of fish growth and effective for enhancing the yield of 2546 kg/ha compared to ambient temperature in open units.•The rate of survival and net weight gain of different species of fish especially Japanese punti and fresh water prawn were distinctly higher in the mimicked greenhouse compared to open ones.•The score values of the sum total of the integrated ecological conditions revealed 36% enhanced fish yield due to ~ 5ºC rise in water temperature during winter, mediated through microbial driven enhanced manure mineralization leading to greater abundance of food and ecological integrity.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
PDF
