Unlocking integrated waste biorefinery approach by predicting calorific value of waste biomass.

The current study analyzed the high heating values (HHVs) of various waste biomass materials intending to the effective management and more sustainable consumption of waste as clean energy source. Various biomass waste samples including date leaves, date branches, coconut leaves, grass, cooked macaroni, salad, fruit and vegetable peels, vegetable scraps, cooked food waste, paper waste, tea waste, and cardboard were characterized for proximate analysis. The results revealed that all the waste biomass were rich in organic matter (OM). The total OM for all waste biomass ranged from 79.39% to 98.17%. Likewise, the results showed that all the waste biomass resulted in lower ash content and high fixed carbon content associated with high fuel quality. Based on proximate analysis, various empirical equations (HHV=28.296-0.2887(A)-656.2/VM, HHV=18.297-0.4128(A)+35.8/FC and HHV=22.3418-0.1136(FC)-0.3983(A)) have been tested to predict HHVs. It was observed that the heterogeneous nature of various biomass waste considerably affects the HHVs and hence has different fuel characteristics. Similarly, the HHVs of waste biomass were also determined experimentally using the bomb calorimeter, and it was observed that among all the selected waste biomass, the highest HHVs (21.19 MJ kg-1) resulted in cooked food waste followed by cooked macaroni (20.25 MJ kg-1). The comparison revealed that experimental HHVs for the selected waste biomass were slightly deviated from the predicted HHVs. Based on HHVs, various thermochemical and biochemical technologies were critically overviewed to assess the suitability of waste biomass to energy products. It has been emphasized that valorizing waste-to-energy technologies provides the dual benefits of sustainable management and production of cleaner energy to reduce fossil fuels dependency. However, the key bottleneck in commercializing waste-to-energy systems requires proper waste collection, sorting, and continuous feedstock supply. Moreover, related stakeholders should be involved in designing and executing the decision-making process to facilitate the global recognition of waste biorefinery concept.

Inhibition of the SERCA Ca2+ pumps by curcumin. Curcumin putatively stabilizes the interaction between the nucleotide-binding and phosphorylation domains in the absence of ATP.

Curcumin is a compound derived from the spice, tumeric. It is a potent inhibitor of the SERCA Ca2+ pumps (all isoforms), inhibiting Ca2+-dependent ATPase activity with IC50 values of between 7 and 15 microm. It also inhibits ATP-dependent Ca2+-uptake in a variety of microsomal membranes, although for cerebellar and platelet microsomes, a stimulation in Ca2+ uptake is observed at low curcumin concentrations (<10 microm). For the skeletal muscle isoform of the Ca2+ pump (SERCA1), the inhibition of curcumin is noncompetitive with respect to Ca2+, and competitive with respect to ATP at high curcumin concentrations ( approximately 10-25 microm). This was confirmed by ATP binding studies that showed inhibition in the presence of curcumin: ATP-dependent phosphorylation was also reduced. Experiments with fluorescein 5'-isothiocyanate (FITC)-labelled ATPase also suggest that curcumin stabilizes the E1 conformational state. The fact that FITC labels the nucleotide binding site of the ATPase (precluding ATP from binding), and the fact that curcumin affects FITC fluorescence indicate that curcumin must be binding to another site within the ATPase that induces a conformational change to prevent ATP from binding. This observation is interpreted, with the aid of recent structural information, as curcumin stabilizing the interaction between the nucleotide-binding and phosphorylation domains, precluding ATP binding.

Effect of amino acids on inhibition of lactate dehydrogenase-X by gossypol.

Gossypol acetic acid (GAA) has been shown to have male antifertility effects, but there are pronounced differences among animal species. In the search of endogenous effector molecules, which interfere with the functions of GAA, we have studied the in vitro effect of various amino acids on the inhibition of the purified LDH-X by GAA. Histidine, cysteine and glycine were shown to block the effect of GAA. The effects of these amino acids were concentration dependent. Histidine and glycine protection was found to be complex type in which both the Km and Vmax were decreased compared to control. Arginine, glutamic acid, phenylalanine and valine were found to be ineffective against the inhibitory action of GAA.

The isoenzyme forms of lactate dehydrogenase from the testes of Uromastix hardwickii.

Lactate dehydrogenase was purified from testes of Uromastix hardwickii. The enzyme did not bind to DEAE-Sepharose at pH 7.2. A gel electrophoretic study of the crude enzyme showed the presence of three isoenzymes. The pH optima for pyruvate reduction and lactate oxidation were 7.0 and 9.5, respectively. The purified enzyme showed a single band after SDS-PAGE corresponding to a molecular weight of 34 KDa. The Km values for pyruvate, NADH, lactate and NAD+ were 0.019, 0.045, 9.0 and 0.011 mM, respectively. Pre-heating of the enzyme showed that it was stable up to 70 degrees C.

Estimation and separation of N-acetyl-beta-D-glucosaminidase isoenzymes in urine.

N-acetyl-beta-D-glucosaminidase is a lysosomal enzyme made up of two isoenzymes (A and B). It has been used extensively as a marker for kidney damage. However, its estimation in urine has not been standardized. We have established a method for the estimation and separation of NAG isoenzymes by ion-exchange chromatography. In 19 experiments done so far, this method has given reproducible results. The significance of this method is that with a single experiment, one can estimate total as well as individual isoenzyme activity. Furthermore, urine constituents do not appear to interfere in this assay.

Determination of pentose phosphate and Embden-Meyerhof pathway activities in bovine embryos.

Quantitative determination was made of the activity of pentose phosphate pathway (PPP) and Embden-Meyerhof pathway (EMP) in individual bovine embryos from the six-cell to the hatched blastocyst stage. Embryos were collected from superovulated cross-bred heifers and classified into good and poor categories. A single embryo in 1 microl of medium was mixed with 2 microl of medium containing 3 to 30 nCi radiolabeled glucose previously placed on a detached lid of the 1.5-ml polypropylene microcentrifugé vial. The lid was then fitted to its vial which had been loaded in advance with 1.5 ml of 0.1 N NaOH. Vials were then incubated at 37 degrees C for 3 h. At the end of the incubation period, a 1.5-ml NaOH trap was inverted and placed into a 20-ml scintillation vial containing 10 ml of aqueous counting solution and counted in a liquid scintillation spectrophotometer. The PPP activity in good-quality embryos was greatest at the six-cell stage and decreased with increasing embryo development. The EMP activity showed the reverse trend. Poor- quality embryos had a lower glucose metabolism and higher PPP activity. Similar measurements were made on embryos following 24 h of culture, and total glucose metabolism and percentage of PPP activity were increased. In conclusion, these data suggest that in good quality bovine embryos total glucose utilization is low until 16-cell stage, with PPP being the predominant pathway. Total glucose utilization increases significantly at the morula stage; EMP activity increases with increasing embryo development; and PPP activity increases significantly in poor quality embryos and in embryos 24 h in culture.

Bovine amniotic and allantoic fluids for the culture of murine embryos.

This study evaluated bovine amniotic and allantoic fluids as culture media for two-cell murine embryos to the hatched blastocyst stage. Amniotic and allantoic fluids were collected from four 70-d periods of pregnancy and pooled from at least five different animals. In Experiment 1 (n=470) the fluids were frozen twice. Treatments consisted of twice frozen amniotic or allantoic fluid from each pregnancy period, Whitten's medium and fetal calf serum. The later two media were controls. Twice-frozen amniotic fluid<70 d pregnancy period, fetal calf serum and Whitten's medium supported the development of embryos to the hatched blastocyst stage. Whitten's medium was superior to twice-frozen amniotic fluid<70 d pregnancy period or fetal calf serum (P<0.01). Biochemical analysis showed lower glucose in amniotic and allantoic fluids than in Whitten's medium. Experiment 2 (n=425) was performed to evaluate the effect of glucose supplementation to amniotic fluid. No benefit of glucose supplementation of the amniotic fluid was observed. In Experiment 3 (n=432), the fluids were transported nonfrozen on ice. Treatments consisted of nonfrozen amniotic fluid<70 d pregnancy period; nonfrozen amniotic fluid<70 d pregnancy period+glucose), nonfrozen allantoic fluid<70 d pregnancy period; and Whitten's medium. The percentages of embryos developing to hatched blastocyst stage were 66.6, 56.5, 57.4 and 63.9% respectively, for each of the four treatments. No differences were found between any two treatments (P<0.05). In Experiment 4 (n=231) the fluids were stored at -20 degrees C for 15 d. Whitten's medium was superior to amniotic or allantoic fluid<70 d pregnancy period in sustaining embryo development (P<0.05). In conclusion, these data indicate that nonfrozen bovine amniotic or allantoic fluid<70 d pregnancy period can support the development of murine embryos to the hatched blastocyst stage comparable to culture in Whitten's medium. Glucose supplementation of the amniotic fluid offered no advantage, and freezing of fluids had an adverse effect on in vitro embryo development.

Lactate dehydrogenase from gastrocnemius muscle of turtle.

Five bands of lactate dehydrogenase (LDH) isoenzymes were seen by polyacrylamide gel electrophoresis in gastrocnemius muscle of the turtle (Kachuga smithi). The major band was of M2H2 type and was partially purified by gel filtration and affinity chromatography. The specific activity of the enzyme was 2.6 units/mg protein. The half-life of the enzyme at 4 degrees C, was about 7 days. The optimum temperature for enzyme activity was 30 degrees C and the enzyme was irreversibly inactivated at 40 degrees C. The optimum pH for the forward reaction (pyruvate to lactate) was 5.5, while for reverse reaction it was between 8.0 to 9.5. The apparent Km values for pyruvate, NADH, lactate and NAD+ were 0.20, 0.013, 25 and 0.333 mM, respectively. Oxalate was found to be the inhibitor of LDH with Ki of about 4.2 mM.

The effect of caffeine on normal and denervated gastrocnemius muscles of Uromastix hardwickii.

The effect of time and 5 mM caffeine was studied on the maximum twitch tension of the normal and 11-13 days denervated gastrocnemius muscles of Uromastix hardwickii. The maximum twitch tension was found to decrease with time and it remained about 68% of initial after 60 minutes at 20 degrees C. Five mM caffeine only produced potentiation in normal and denervated muscles while there was no contracture in either muscle. Although caffeine increased the overall contraction and relaxation times in control muscles, it was more effective on the contraction time of the denervated muscles in which the contraction time increased with time. Denervated muscles were seen to be less sensitive to caffeine as the contraction times increased with time (at about 30-40 minutes) in these muscles while in normal control muscles the contraction time increased immediately. The action of caffeine in relation to these effects is discussed.