Aims: In recent studies, xylanase is the valuable enzyme in paper industry, and the demand of this enzyme is increasing. The finding out of the new xylanases with good properties and applicable for paper industries from Indonesian biodiversity is still required. In this study, we isolated, cloned, and expressed the gene encoding alkalophilic xylanase gene from Indonesia indigenous Bacillus halodurans CM1 in Escherichia coli, and applied the recombinant xylanase in deinking process. Methodology and results: The open reading frame of the gene consist of 1191 bp, with nucleotide identity 99% with that of B. halodurans C-125 has been obtained by using PCR. The gene was submitted into GenBank with accession number KU759320. The gene was then subcloned and expressed in E.coli using pET 21d(+) vector, and we found that only extracellular that have significant activity. The gene product had optimum activity at 65 °C and pH 9. After purification using Ni-NTA, the single band was obtained, and the molecular mass was about 45 kDa based on SDS/PAGE analyses. The recombinant xylanase had been applied in deinking process of old news paper at laboratory scale of a paper industry. This recombinant xylanase application showed better brightness and whiteness, as well as higher brightness and whiteness gain of of product compared to the commercial one when using the same raw material. Conclusion, significance and impact of study The study is the first example of the cloning of industrially important enzyme (xylanase) from B. halodurans CM1 and showed potential application of the recombinant enzyme in deinking process of waste paper.

An attractive smile enhances the appearance and acceptance of an individual in society. Gum exposure more than 3 mm is generally considered unattractive and known as a gummy smile, which is usually considered an aesthetic problem. At present, patients have a greater desire for more aesthetic results that may influence the planning of dental treatments. This case report aimed to describe the surgical sequence of aesthetic crown lengthening to improve smile profile and eliminate gummy smile. We reported a 21-year-old non-smoking woman with no pertinent medical history who presented with a chief complaint of an unattractive smile due to excessive gingival display. The gingival display in the smile was 5 mm, and the width to height ratio of the central incisor was 121%. Neither periodontal problems nor teeth mobility was detected. Assessment for the condition was excessive gingival display due to altered passive eruption. The overall prognosis for this case was good. The primary treatment plan proposed to the patient was an aesthetic crown lengthening. Altered passive eruption class I subtype A was a case conclusion, and aesthetic crown lengthening with gingivectomy without osseous reduction was the selected treatment. In conclusion, aesthetic crown lengthening should be considered as a surgical component of aesthetic therapy to improve smile profile and eliminate gummy smile.
Crown Lengthening ; Gingivectomy