No abstract

The marine dinoflagellate genus Alexandrium includes a number of species that produce potent neurotoxins responsible for paralytic shellfish poisoning, which in humans may cause muscular paralysis, neurological symptoms and, in extreme cases, death. Because of the genetic diversity of different genera and species, molecular tools may help to detect the presence of target microorganisms in marine field samples. Here we employed a loop-mediated isothermal amplification (LAMP) method for the rapid and simple detection of toxic Alexandrium species. A set of four primers were designed based upon the conserved region of the 5.8S rRNA gene of members of the genus Alexandrium. Using this detection system, toxic Alexandrium genes were amplified and visualized as a ladder-like pattern of bands on agarose gels under isothermal condition within 60 min. The LAMP amplicons were also directly visualized by eye in the reaction tube by the addition of SYBR Green I. This LAMP assay was 10-fold more sensitive than a conventional PCR method with a detection limit of 5 cells per tube when targeting DNA from Alexandrium minutum. The LAMP assay reported here indicates the potential usefulness of the technique as a valuable simple, rapid alternative procedure for the detection of target toxic Alexandrium species during coastal water monitoring.

Olive pomace (OP) was used as raw material to extract cellulose by multi-step chemical method, and the extracted cellulose was characterized. The two steps of alkali treatment (alkali concentration, reaction time and reaction temperature) and bleaching (H2O2 concentration, NaOH concentration, bleaching time and bleaching temperature) were optimized. The results showed that the optimum conditions for alkali treatment were as follows: alkali concentration 6%, reaction time 2 h, reaction temperature 95°C; the optimal bleaching conditions were as follows: 7.5% H2O2 solution, 5% NaOH, bleaching time 2 h, bleaching temperature 75°C. After multi-step chemical treatment, the cellulose content of the final OP cellulose was (86.41 ± 0.27) %, the lignin content was (6.77 ± 0.55) %, the extraction process yield was 20.36%. By scanning electron microscopy, the surface of OP cellulose changes from dense smooth structure to rough irregular structure with different treatment degrees. Fourier transform infrared spectroscopy (FTIR) proved the removal of hemicellulose and lignin in OP fibers after chemical treatment. The crystallinity of OP fiber increased from 34.80–68.69% after treatment. Thermogravimetric analysis (TGA) showed that OP cellulose had high thermal stability. The study provides a new idea for the conversion of industrial processing by-products into high-quality cellulose, and proves that it is feasible to extract cellulose from olive pomace.

Olive pomace (OP) was used as raw material to extract cellulose by multi-step chemical method, and the extracted cellulose was characterized. The two steps of alkali treatment (alkali concentration, reaction time and reaction temperature) and bleaching (H 2 O 2 concentration, NaOH concentration, bleaching time and bleaching temperature) were optimized. The results showed that the optimum conditions for alkali treatment were as follows: alkali concentration 6%, reaction time 2 h, reaction temperature 95°C; the optimal bleaching conditions were as follows: 7.5% H 2 O 2 solution, 5% NaOH, bleaching time 2 h, bleaching temperature 75°C. After multi-step chemical treatment, the cellulose content of the nal OP cellulose was (86.41 ± 0.27) %, the lignin content was (6.77 ± 0.55) %, the extraction process yield was 20.36%. By scanning electron microscopy, the surface of OP cellulose changes from dense smooth structure to rough irregular structure with different treatment degrees. Fourier transform infrared spectroscopy (FTIR) proved the removal of hemicellulose and lignin in OP bers after chemical treatment. The crystallinity of OP ber increased from 34.80-68.69% after treatment. Thermogravimetric analysis (TGA) showed that OP cellulose had high thermal stability. The study provides a new idea for the conversion of industrial processing by-products into high-quality cellulose, and proves that it is feasible to extract cellulose from olive pomace.