| 1. |
- Ahmed, Ajaj, et al.
(author)
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Evaluation of Thar Desert bacterial lipases for catalytic efficiencies and biodiesel production potentials
- 2023
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In: Biologia. - : Springer Nature. - 0006-3088 .- 1336-9563. ; 78:4, s. 1187-1197
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Journal article (peer-reviewed)abstract
- The present work describes the screening of thermotolerant bacteria isolated from Thar Desert environmental samples for lipase activity and their catalytic efficiencies, such as tolerance to extreme pHs, temperatures, and organic solvents, and efficiency to synthesize biodiesel from waste cooking oils. The selected lipases were thermos-alkaliphilic in nature showing good activity at higher temperatures and in the alkaline pH range with optimal activity at 45 °C and pH 8 or 9. The lipases efficiently converted oils to biodiesel (fatty acid methyl ester), giving up to 78% conversion under specific reaction conditions. The enzyme (lipase) mediated biodiesel production will soon offer an eco-friendly and sustainable energy source for automobiles and industrial applications. The thermos-alkaliphilic properties of these lipases along with their efficiency to produce fatty acid methyl ester from waste cooking oil and methanol as well as other prospective applications, make them potential candidates for biodiesel production and other prospective applications such as the synthesis of flavor and fragrance esters and remediation of various environmental pollutants.
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| 2. |
- Andersson, Michael R., et al.
(author)
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Mutational analysis of conserved glutamic acids of Pho89, a Saccharomyces cerevisiae high-affinity inorganic phosphate:Na+ symporter
- 2012
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In: Biologia. - : Springer Science and Business Media LLC. - 0006-3088 .- 1336-9563. ; 67:6, s. 1056-1061
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Journal article (peer-reviewed)abstract
- In Saccharomyces cerevisiae, the high-affinity phosphate transport system comprises the Pho84 and Pho89 permeases. The Pho89 permease catalyzes import of inorganic phosphate in a symport manner by utilizing Na+ ions as co-solute. We have addressed the functional importance of two glutamic acid residues at positions 55 and 491. Both residues are highly conserved amongst members of the inorganic phosphate transporter (PiT) family, which might be an indication of functional importance. Moreover, both residues have been shown to be of critical importance in the hPit2 transporter. We have created site-directed mutations of both E55 and E491 to lysine and glutamine. We observed that in all four cases there is a dramatic impact on the transport activity, and thus it seems that they indeed are of functional importance. Following these observations, we addressed the membrane topology of this protein by using several prediction programs. TOPCONS predicts a 7-5 transmembrane segment organization, which is the most concise topology as compared to the hPiT2 transporter. By understanding the functionality of these residues, we are able to correlate the Pho89 topology to that of the hPiT2, and can now further analyze residues which might play a role in the transport activity.
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| 3. |
- Arslan, N., et al.
(author)
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Aquatic Oligochaeta (Annelida) of Balıkdamı wetland (Turkey), with description of two new species of Phallodrilinae
- 2007
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In: Biologia. - : Springer Science and Business Media LLC. - 0006-3088 .- 1336-9563. ; 62:3, s. 323-334
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Journal article (peer-reviewed)abstract
- The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivrihisar (Eskişehir, Central Anatolia), is one of the most important bird conservation areas in Turkey. This area also encompasses the mouth of the torrential Göksu Stream, which is partly hyporheic. During this study (2001–2003), 1,471 specimens representing 34 taxa of aquatic Oligochaeta were collected from the Balıkdamı Wetland. All the species identified are new records for Balıkdamı. Two species, Coralliodrilus amissus sp. n. and Gianius anatolicus sp. n., are new to science, and five species, Stylodrilus parvus (Hrabě et Černosvitov, 1927), Chaetogaster diastrophus (Gruithuisen, 1828), Peipsidrilus libanus (Giani et al., 1982), Tubifex acuticularis Martinez-Ansemil et Giani, 1983, and Epirodrilus moubayedi Giani et Martinez-Ansemil, 1983, are new records for Turkey. Two other species, Peipsidrilus libanus and Tubifex acuticularis, are re-described. The oligochaete fauna of the wetland was dominated by widely distributed tubificid taxa. The lumbriculid Stylodrilus parvus was the most abundant species in the Göksu stream. The two new phallodriline species are remarkable since most representatives of this subfamily live in the marine environment. Due to the species richness and diversity of Oligochaeta, as well as of several other animal groups, the Balıkdamı wetland area deserves conservation.
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| 4. |
- Brodin, Yngve, et al.
(author)
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Smaller, lighter coloured and less hairy Procladius (Diptera, Chironomidae) in warmer climate
- 2023
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In: Biologia. - : Springer Nature. - 0006-3088 .- 1336-9563. ; 78:8, s. 2091-2098
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Journal article (peer-reviewed)abstract
- The relationship between body size, colour and hairiness of Procladius of the Diptera family Chironomidae and climate measured as annual mean air temperature was analysed. The study was based on 453 males representing 31 species from 253 localities in 27 countries in Europe and six elsewhere. Wing length as well as three other characters reflecting body size showed significant decrease with warmer climate conditions. The results are in line with several other studies of insects concluding that adult insects are smaller in warmer climate, also considering the implications of global warming. Likewise, all five characters representing colour lightness showed significantly lighter coloured Procladius specimens with warmer climate. The relationship between hairiness and annual mean air temperature was weaker than that of size or colour and temperature, but all five characters studied showed a statistically significant decrease in hairiness with warmer climate. The biological relevance of smaller size, lighter colour and less hairiness in warmer climate can be related to several factors regulating flight and swarming, including less need of protection against cold weather, overheating avoidance, mating success agility and predator escape.
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| 5. |
- Danilov, Roman A, et al.
(author)
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Periphyton communities on natural substrata in eu-, meso- and oligotrophic lakes at higher latitude
- 2002
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In: Biologia. - 0006-3088 .- 1336-9563. ; 57:4, s. 433-436
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Journal article (peer-reviewed)abstract
- Natural epiphyton and epilithon communities were studied in eu-, meso- and oligotrophic lakes at latitude of 62degrees54' N in Vasternorrlands region of Sweden. The samples of epiphyton as well as epilithon (three per lake) were identical and specific for each lake studied. Both epiphytic and epilithic communities consisted of members of three classes of algae - Cyanophyceae, Chlorophyceae and Bacillariophyceae. The highest species diversity was detected within Chlorophyceae while Cyanophyceae and Bacillariophyceae contained the same amount of species. In general, epiphyton and epilithon shared 44% of species identified. However, both epiphyton and epilithon showed distinct patterns between lakes of different trophic level. Epiphyton in the eutrophic lakes were clearly dominated by Cyanophyceae (Bacillariophyceae co-dominated in one of the eutrophic lakes). Both mesotrophic and oligotrophic lakes were signed by high abundance of Chlorophyceae and almost complete absence of Bacillariophyceae and Cyanophyceae. Epilithic communities in the oligotrophic lakes had higher species diversity than those in the meso- and eutrophic lakes studied. Chlorophyceae were dominant in two eutrophic lakes and Cyanophyceae only in one eutrophic lake, Chlorophyceae as well as Bacillariophyceae were abundant in the oligotrophic lakes. Cluster analysis based on species presence-absence led to a sufficient resolution between both epiphytic and epilithic communities of eutrophic environments, on the one hand, and epiphytic and epilithic communities of meso- and oligotrophic environments, on the other.
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| 6. |
- Danilov, Roman, et al.
(author)
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Effects of copper on growth rate, cell shape, motility and photosynthesis in the green flagellate Euglena gracilis in a long-term experiment
- 2000
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In: Biologia. - 0006-3088 .- 1336-9563. ; 55:4, s. 413-418
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Journal article (peer-reviewed)abstract
- The green flagellate Euglena gracilis was treated for seven days with concentrations of copper ranging from 0.02 mg L-1 to 2.0 mg L-1. No inhibiting effects were detected in any physiological parameters measured. In general, it seems that enhanced copper concentrations stimulated photosynthetic efficiency (PE) of E. gracilis. Concentrations of copper reported to be critical for the other algae studied (from 0.10 mg L-1 to 0.14 mg L-1) did not show any severe negative effects on E. gracilis. An unusual trend was observed where an increase in PE was followed by an increase in light irradiance necessary to achieve light compensation point. High capacity of E. gracilis to adapt to copper stress is being discussed as a possible explanation for the trends detected.
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| 7. |
- Eckstein, Rolf Lutz, et al.
(author)
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Variation in life-cycle between three rare and endangered floodplain violets in two regions : implications for population viability and conservation
- 2009
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In: Biologia. - : Springer Science and Business Media LLC. - 0006-3088 .- 1336-9563. ; 64:1, s. 69-80
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Journal article (peer-reviewed)abstract
- We studied the demography of Viola elatior, V. pumila, and V. stagnina, three rare and endangered Central European floodplain species, to (i) analyse variation in life-cycles among congeners and between regions (Dyje-Morava floodplains, Czech Republic; Upper Rhine, Germany), (ii) to define sensitive stages in the life-cycles, and (iii) to identify possible threats for population viability and species conservation. Matrix models were based on the fate of marked individuals from a total of 27 populations over two years. We analysed population growth rate (lambda), stage distribution, net reproductive rate (R (0)), generation time, age at first reproduction, and elasticity and calculated a life table response experiment (LTRE). Most populations were declining and lambda did not differ between species or regions during the observed interval. Despite higher probabilities for survival and flowering in the Dyje populations, R (0) was higher in the Rhine populations. Also other demographic traits showed consistent differences between regions and/or species. Complex life-cycles and large variation in lambda precluded unequivocal identification of sensitive stages or vital rates for conservation. Variation between regions may be a consequence of differences in habitat quality. Our results suggest that deterministic processes such as reduced management, succession, habitat destruction, and lack of disturbance through reduced or eliminated flooding present the strongest threat for the viability and persistence of populations of the three floodplain violets as compared with stochastic processes. However, the persistent seed bank of the species may buffer populations against environmental variation and represents a reservoir for recovery after resumption of suitable land-use management.
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| 8. |
- Ekelund, Nils, 1956-, et al.
(author)
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Effects of autumnal stratification on phytoplankton communities in Lake Solumsjö, Sweden: Application of diversity indices and multivariate methods
- 2000
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In: Biologia. - 0006-3088 .- 1336-9563. ; 55:4, s. 357-362
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Journal article (peer-reviewed)abstract
- Effects of autumnal stratification on phytoplankton communities at different depths were studied in Lake Solumsjö, NE Sweden. Species number, Shannon-Weaver’s, Margalef’s and Menhinick’s indices as well as cluster analyses using presence-absence with abundance matrices were applied. All diversity indices used clearly indicated higher diversity in epilimnion compared to that in hypolimnion. This pattern can be explained by sole dominance of Trachelomonas volvocinopsis under predominantly anoxic conditions and high concentrations of iron and manganese below the thermal gradient. Stratification disappeared between September 29 and October 4, thus leading to homogenisation of water column and similar phytoplankton communities at all depths. Cluster analyses using presence-absence with abundance matrices turned out to be a powerful tool when studying temporal changes in phytoplankton communities as a result of stratification patterns. Two distinct clusters at depths of 0, 2 and 10 m were clearly separated: one containing algal communities during stratification and one containing algal communities after the thermal gradient disappeared. At the depth of 5 m more homogeny between phytoplankton communities under stratified and mixed conditions was observed.
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| 10. |
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