Production of <i>N</i>‑Acetyl‑d‑glucosamine from Mycelial Waste by a Combination of Bacterial Chitinases and an Insect <i>N</i>‑Acetyl‑d‑glucosaminidase

<i>N</i>-Acetyl-d-glucosamine (GlcNAc) has great potential to be used as a food additive and medicine. The enzymatic degradation of chitin-containing biomass for producing GlcNAc is an eco-friendly approach but suffers from a high cost. The economical efficiency can be improved by both optimizing the member and ratio of the chitinolytic enzymes and using new inexpensive substrates. To address this, a novel combination of bacterial and insect chitinolytic enzymes was developed in this study to efficiently produce GlcNAc from the mycelia of Asperillus niger, a fermentation waste. This enzyme combination contained three bacterial chitinases (chitinase A from Serratia marcescens (<i>Sm</i>ChiA), <i>Sm</i>ChiB, <i>Sm</i>ChiC) and one insect <i>N</i>-acetyl-d-glucosaminidase from Ostrinia furnacalis (<i>Of</i>Hex1) in a ratio of 39.1% of <i>Sm</i>ChiA, 26.7% of <i>Sm</i>ChiB, 32.9% of <i>Sm</i>ChiC, and 1.3% of <i>Of</i>Hex1. A yield of 6.3 mM (1.4 mg/mL) GlcNAc with a purity of 95% can be obtained from 10 mg/mL mycelial powder in 24 h. The enzyme combination reported here exhibited 5.8-fold higher hydrolytic activity over the commercial chitinase preparation derived from Streptomyces griseus

Carbon storage in biomass and soils in four <i>C. equisetifolia</i> plantations (Mg ha⁻¹, mean ± S.E.).

<p>Note: SOC, TBCS, AGCS and TCS refer to soil organic carbon (0–100 cm), total biomass C storage, aboveground C storage and total C storage, respectively. Means in a column followed by different lower-case letters are significantly different at <i>P</i><0.05(one-way ANOVA and LSD test).</p

Properties of the soil in four different age classes of <i>C. equisetifolia</i> plantations (only 0–10 and 10–20 cm soil data were presented here, mean ± S.E.).

<p>Note: Means in a row followed by different lower-case letters are significantly different at P<0.05 (one-way ANOVA and LSD test).</p

Average annual rate of biomass carbon accumulation at four age classes of <i>C. equisetifolia</i> plantations (Mg C ha⁻¹yr⁻¹).

<p>Note: AGB refers to aboveground biomass C; BGC refers to belowground biomass C; TBC refers to total biomass C.</p

The soil carbon density of four different age classes of <i>C. equisetifolia</i> plantations.

<p>Note: Error bar indicating SE.</p

Potent 11β-Hydroxylase Inhibitors with Inverse Metabolic Stability in Human Plasma and Hepatic S9 Fractions To Promote Wound Healing

Topical application of CYP11B1 inhibitors to reduce cutaneous cortisol is a novel strategy to promote healing of chronic wounds. Pyridyl substituted arylsulfonyltetrahydro­quinolines were designed and synthesized resulting in a strong inhibitor <b>34</b> (IC₅₀ = 5 nM). It showed no inhibition of CYP17 and CYP19 and no mutagenic effects. It exhibited inverse metabolic stability in plasma (<i>t</i>_1/2 ≫ 150 min), which is similar to wound fluid in composition, and in liver S9 fractions (<i>t</i>_1/2 = 16 min)

Biomass of four different age classes of <i>C. equisetifolia</i> plantations (Mg ha⁻¹, mean ± S.E.).

<p>Note: AGB refers to aboveground biomass, PB refers to total plantation biomass. Means in a column followed by different lower-case letters are significantly different at <i>P</i><0.05 (one-way ANOVA and LSD test).</p

The general status of four age classes of <i>C. equisetifolia</i> plantations in 2011 (mean±S.E.).

<p>Note: DBH: Diameter at breast height. Means in a column followed by different lower-case letters are significantly different at <i>P</i><0.05 (one-way ANOVA and LSD test).</p

The depth distribution of fine root biomass at four age classes of <i>C. equisetifolia</i> plantations (Mg ha⁻¹, mean ± S.E.).

<p>Note: Means in a column followed by different lower-case letters are significantly different at <i>P</i><0.05(LSD test).</p

Additional file 1 of Trajectories in nitrogen availability during forest secondary succession: illustrated by foliar δ15N

Additional file 1. Additional figures and tables