Comparative study of putative 9-cis-epoxycarotenoid dioxygenase and abscisic acid accumulation in the responses of Sunki mandarin and Rangpur lime to water deficit.

Abscisic acid is a plant hormone that participates in essential plant physiological processes, especially during adaptation to many environmental stresses, such as water deficit. The relationship between ABA accumulation and the expression of putative carotenoid cleavage dioxygenase (CCD) genes was investigated in the pot-cultivated leaves and roots of the 'Rangpur' lime and 'Sunki Maravilha' mandarin plants. Transpiration, stomatal resistance and leaf growth were evaluated when these genotypes were subjected to continuous water deficit. Under water deficit conditions, the 'Rangpur' lime extracts used greater amounts of water when compared to the 'Sunki Maravilha' plants, which reached the greatest stomatal resistance 5 days before 'Rangpur' lime. When subjected to water deficit, the roots and leaves of 'Sunki Maravilha' showed a progressive increase in ABA accumulation; however, in 'Rangpur' lime, alternations between high and low ABA concentrations were observed. These results suggest a retroactive feeding regulation by ABA. In 'Rangpur' lime the NCED2, NCED3 and CCD4a genes were expressed at the highest levels in the roots, and NCED5 was highly expressed in the leaves; in 'Sunki Maravilha', the NCED2 and NCED5 genes were most highly expressed in the roots, and NCED2 was most highly expressed in the leaves. However, for both genotypes, the transcription of these genes only correlated with ABA accumulation during the most severe water deficit conditions. The 'Rangpur' lime behaved as a vigorous rootstock; the leaf growth remained unaltered even when water was scarce. However, 'Sunki Maravilha' adaptation was based on the equilibrium of the response between the root and the aerial tissues due to water restriction. The use of the Sunki mandarin in combination with a scion with similar characteristics as its own, which responds to water deficit stress by accumulating ABA in the leaves, may display good drought tolerance under field conditions.

Production of thermophilic endo-ß-1,4-xylanases by Aspergillus fumigatus FBSPE-05 using agro-industrial by-products.

In the present paper, endo-ß-1,4-xylanase production by Aspergillus fumigatus was evaluated in solid-state fermentation using low-cost substrates such as sugarcane bagasse (SCB), brewer's spent grain (BSG), and wheat bran (WB). The partial characterization of the crude enzyme was also performed. In the experimental conditions, the highest levels of endo-ß-1,4-xylanase production by A. fumigatus FBSPE-05 occurred within 8 days incubation when using SCB/liquid medium at 1:2 ratio (219.5 U g(-1)) and 4 days incubation when using WB/liquid medium at 1:1 ratio (215.6 U g(-1)). Crude enzyme from this last condition was used to enzyme characterization, showing best enzyme activity at 60 °C and pH 6.0, which suggests a thermophilic endoxylanase. The crude enzyme retained 73% of its activity after 1 h at 60 °C, and zymogram has shown three bands of endo-ß-1,4-xylanase activity, with different molecular masses. A. fumigatus FBSPE-05 was able to grow and produce good levels of endo-ß-1,4-xylanase using agro-industrial by-products, making this strain worthy for further investigation. To our knowledge, this is the first study reporting the use of SCB and/or BSG as sole substrates for endoxylanase production by solid-state fermentation using A. fumigatus.

Aspergillus fumigatus thermophilic and acidophilic endoglucanases.

This study evaluated the production of cellulolytic enzymes by an Aspergillus fumigatus strain, isolated from sugar cane bagasse, according to its ability to grow on microcrystalline cellulose as the sole carbon source. The effect of the carbon source (brewer's spent grain, sugarcane bagasse, and wheat bran) and of the nitrogen source (corn steep liquor and sodium nitrate) on cellulase production was studied using submerged and solid state cultivations at 30 degrees C. The highest levels of endoglucanase (CMCase) corresponded to 365 U L(-1) and was obtained using sugarcane bagasse (1%) and corn steep liquor (1.2%) in submerged fermentation within 6 days of cultivation. This supernatant was used to run a sodium dodecyl sulfate polyacrylamide gel electrophoresis that showed six bands with endoglucanase activity. CMCase activity was higher at 65 degrees C and pH 2.0, indicating that this microorganism produces a thermophilic and acid endoglucanase. Solid state cultivation favored FPase production, that reached 47 U g(-1) of dry substrate (wheat bran and sugarcane bagasse) within 3 days.

Observations on categorisation of new TB cases: implications for controlling drug resistance.

In the context of rising rates of drug-resistant tuberculosis (TB) in India, this communication presents some field observations during screening of new cases registered with the Revised National Tuberculosis Control Programme (RNTCP) in urban and rural areas of Maharashtra, India. It appears that erroneous categorisation and treatment that contributes to multiple drug resistance results from a lack of patient screening for previous treatment, ambiguity in categorisation and reluctance to disclose a history of anti-tuberculosis treatment. Suggested measures include detailed screening of new cases, computerisation of patient records and an empathetic dialogue between patient and health care provider.

Rhodococcus and Mycobacterium Tuberculosis: masquerade or mixed infection.

Rhodocci have a morphology similar to that of Mycobacterium tuberculosis (TB), and are indistinguishable from normal diphtheroid flora. Symptoms include fever, productive/non-productive cough and pleuritic chest pain. Rhodococcal infections, being resistant to routine anti-tuberculosis medications, may be misdiagnosed as drug-resistant TB, thus prompting treatment for TB with rifampicin-containing regimens that promote the emergence of resistance. We present here a sputum smear AFB-positive case who, although clinically cured, remains unresolved despite a series of technological investigations as to the cause of infection being purely rhodococci or mixed infection with M. tuberculosis.

Honey bee attractants and pollination in sweet orange, Citrus sinensis (L.) Osbeck, Var. Pera-rio

This experiment studied the frequency and behavior of insects on sweet orange flowers, Citrus sinensis (L.) Osbeck, their effect on fruit production (quantity and quality), nectar and pollen collection