An Alkalothermophilic Amylopullulanase from the Yeast Clavispora lusitaniae ABS7: Purification, Characterization and Potential Application in Laundry Detergent

In the present study, α-amylase and pullulanase from Clavispora lusitaniae ABS7 isolated from wheat seeds were studied. The gel filtration and ion-exchange chromatography revealed the presence of α-amylase and pullulanase activities in the same fraction with yields of 23.88% and 21.11%, respectively. SDS-PAGE showed a single band (75 kDa), which had both α-amylase (independent of Ca2+) and pullulanase (a calcium metalloenzyme) activities. The products of the enzymatic reaction on pullulan were glucose, maltose, and maltotriose, whereas the conversion of starch produced glucose and maltose. The α-amylase and pullulanase had pH optima at 9 and temperature optima at 75 and 80 °C, respectively. After heat treatment at 100 °C for 180 min, the pullulanase retained 42% of its initial activity, while α-amylase maintained only 38.6%. The cations Zn2+, Cu2+, Na+, and Mn2+ increased the α-amylase activity. Other cations Hg2+, Mg2+, and Ca2+ were stimulators of pullulanase. Urea and Tween 80 inhibited both enzymes, whereas EDTA only inhibited pullulanase. In addition, the amylopullulanase retained its activity in the presence of various commercial laundry detergents. The performance of the alcalothermostable enzyme of Clavispora lusitaniae ABS7 qualified it for the industrial use, particularly in detergents, since it had demonstrated an excellent stability and compatibility with the commercial laundry detergents.

Reusable textile microfiber and laundry in healthcare: Critical analysis of problematic published information

Recent analyses of environmental services products and practices in healthcare have covered the concepts of hygienically clean, mechanisms of cleaning, and comparison of reusable and disposable textile microfiber products. In 11 referred papers, it was discovered that three had sufficient factual errors to influence the citations found in the broader literature. This study evaluating these problematic papers is an obligation of the scientific community for accuracy. In light of newer data on the efficacy of important textiles for microfiber cleaning, these previous studies were reexamined to see if methodological corrections are needed. Closer investigation of the authors’ data was used to ascertain the validity of their initial conclusions. These current reevaluations reverse conclusions in these journal articles. It appears factors such as multi-variant statistical comparisons, combining variables, and use of extremely high inoculum for cleaning led to the wrong conclusions in these three papers. The revised results show that for hospital surface cleaning with reusable textile microfiber products, no detectable levels were found for two of the most challenging organisms for hospital-acquired infections, methicillin-resistant Staphylococcus aureus and Clostridium difficile. Commercial laundry was substantially better than hospital laundry and reusable microfiber products improved with use.

Artificial Neural Networks and Response Surface Methodology Approach for Optimization of an Eco-Friendly and Detergent-Stable Lipase Production from Actinomadura Keratinilytica Strain Cpt29

This work mainly focused on the production of an efficient, economical, and eco-friendly lipase (AKL29) from Actinomadura keratinilytica strain Cpt29 isolated from poultry compost in north east of Algeria, for use in detergent industries. AKL29 shows a significant lipase activity (45 U/mL) towards hydrolyzed triacylglycerols, indicating that it is a true lipase. For maximum lipase production the modeling and optimization of potential culture parameters such as incubation temperature, cultivation time, and Tween 80 (v/v) were built using RSM and ANN approaches. The results show that both the two models provided good quality predictions, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities. A 4.1-fold increase in lipase production was recorded under the following optimal condition: incubation temperature (37.9 °C), cultivation time (111 h), and Tween 80 (3.27%, v/v). Furthermore, the partially purified lipase showed good stability, high compatibility, and significant wash performance with various commercial laundry detergents, making this novel lipase a promising potential candidate for detergent industries.

Physicochemical assessment of urban wastewater of Cotonou (Benin)

The present study aims to fill the data gap analysis in urban wastewaters characteristics in Benin and its statistical analysis. Physicochemical parameters such as pH, electrical conductivity (EC), Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Total Kjeldahl Nitrogen (TKN), Total Phosphorus (TP) and UV Absorbance at 254 nm, were determined on domestic (greywater and blackwater) and industrial (hospital, pharmaceutical and commercial laundry) wastewater in Cotonou city. Analysis of variance showed a strong significant difference in the physico-chemistry of the various effluents. The pharmaceutical wastewater has the highest concentration of organic pollution (COD = 5,912 ± 1,026 mg/L, Abs.UV254 = 2.667 ± 0.327 cm−1). The organic load of blackwater is mainly in particulate and biodegradable form. Besides, the correlation study showed the limits of pH and EC as an indicator of organic load. Furthermore, the choice of COD or BOD5 as the main design parameter would be limited to blackwater treatment. Abs.UV254 was found to be the parameter having a strong relationship with other parameters of all effluents except blackwater. It then takes priority over COD for the treatment of greywater and industrial wastewater. For future wastewater treatment plant design, we recommend to consider Abs.UV254 as an important parameter.

Extracellular Production, Characterization, and Engineering of a Polyextremotolerant Subtilisin-Like Protease From Feather-Degrading Thermoactinomyces vulgaris Strain CDF

Here, the gene encoding a subtilisin-like protease (protease Als) was cloned from Thermoactinomyces vulgaris strain CDF and expressed in Escherichia coli. The recombinant enzyme was released into the culture medium of E. coli as a mature form (mAls). Purified mAls displayed optimal activity at 60–70°C and pH 10.0 using azo-casein as the substrate, and showed a half-life of 13.8 h at 70°C. Moreover, the activity of thermostable mAls was comparable to or higher than those of mesophilic subtilisin Carlsberg and proteinase K at low temperatures (10–30°C). Protease Als was also stable in several organic solvents and showed high compatibility with commercial laundry detergents. Notably, mAls exhibited approximately 100% of its activity at 3 M NaCl, and showed enhanced thermostability with the increase of NaCl concentration up to 3 M. Protease Als possesses an excess of solvent-accessible acidic amino acid residues, which may account for the high halotolerance of the enzyme. Compared with homologous protease C2 from the same strain, protease Als exhibits substantially lower activity toward insoluble keratin substrates but efficiently hydrolyzes soluble keratin released from chicken feathers. Additionally, direct substitution of the substrate-binding site of protease Als with that of protease C2 improves its activity against insoluble keratin substrates. By virtue of its polyextremotolerant attribute and kerationolytic capacity, protease Als may find broad applications in various industries such as laundry detergents, food processing, non-aqueous biocatalysis, and feather processing.

Heat-based Decontamination of N95 Masks Using a Commercial Laundry Dryer

We propose a dry heat method for decontaminating N95 masks of SARS-CoV-2, designed around placing them in resealable plastic bags, packed in large cardboard boxes installed at the rear end of commercial laundry dryers. Our protocol rests on data collected in collaboration with Alliance Laundry Systems (ALS) and the CDC/NIOSH laboratories, under the "NPPTL Respirator Assess- ments to Support the COVID-19 Response" initiative. We test the two most widely available ALS tumbler models, the UTF75N and UT075N, and show that if our procedure is carefully followed, the masks will be subject to suitably high and stable temperatures for decontamination; in particular the masks will be heated to at least 80C for at least 65 min. For the mask models 3M 1860, 3M 8511, and Halyard 62126, we establish that they pass quantitative fit tests and retain sufficient filtration performance after three cycles of our decontamination procedure. All masks used in this study were new and uncontaminated: the evidence for the levels of biological inactivation of SARS-CoV-2 is provided by [1]. While the protocol outlined here is currently specific to certain tested dryer models, this equipment is widely available, with machines estimated to be within 15 minutes of most US hospitals. Models from other manufacturers may also be appropriate for this decontamination method, though we stress the need for explicit testing on alternative models before use.

Successful Removal of Clostridioides Difficile Spores and Pathogenic Bacteria From a Launderable Barrier Using a Commercial Laundry Process

Background: To properly clean and disinfect hospital mattresses, bed manufacturers recommend a 3- to 6-step process to remove all pathogenic bacteria. An alternative is to use a removable barrier on the mattress, which is laundered after each use. The current study was to determine efficacy of a commercial laundry process in eliminating Clostridioides difficile (C diff) spores, Mycobacterium terrae (M terrae), methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa (P aeruginosa), Klebsiella pneumoniae (K pneumoniae), and Escherichia coli (E coli) from a barrier. Methods: A test barrier received 3 unique microbial suspensions in separate locations, each suspension having a known quantity of specific microorganisms: C diff spores, M terrae, and a mixed suspension of MRSA, S aureus, P aeruginosa, K pneumoniae, and E coli. A wash load contained the test barrier and 11 additional ballast barriers. Various soils were spread onto the barriers to simulate heavy soiling that may occur in a wash load: Each barrier received a small amount of mixed soil, 50% received urine, 25% received blood, and 25% received a large amount of additional mixed soil. The load was laundered using 71°C (160°F) water, detergent, and chlorine bleach, with final drying at 71°C (160°F). After laundering, remaining colony-forming units (CFUs) of each microorganism were counted at the applied locations. Each test was replicated 3 times. Industry-accepted methods were used to produce suspensions, apply inoculum, and recover organisms after laundering. Results: Before laundering, test barriers contained at least 7.0 log10 cfu/mL of each microorganism distributed over 103 cm2. After laundering, in all cases, no residual CFUs were detected over the test area, resulting in greater than 6.0 log10 reductions for every organism. ( P < .05). Conclusions: Under extreme test conditions including the presence of soil, the laundry process removed all detectable pathogenic bacteria and spores from the barrier.

“Forced Selling,” Domesticity, and the Diffusion of Washing Machines in Interwar America

This article explores the reasons behind the relatively slow diffusion of washing machines in interwar America and the rise and decline of a distinctive marketing strategy employed to accelerate diffusion: door-to-door sales. Washers represented a particularly difficult selling challenge, as many white-collar households (and, in the South, most white families) had already outsourced some, or all, of their washing, to a laundress or a commercial laundry. Consumer resistance to machine washing was particularly strong in the South, reflecting both the greater availability and lower cost of black domestic servants, together with attitudes, inherited from the slavery era, that clothes washing was beneath the dignity of white women. During the 1920s, washers were mainly sold door-to-door, by salesmen who focused primarily on the large number of blue-collar families who relied on manual home washing. The Depression witnessed a change in the washer market, with a greater emphasis on over-the-counter selling and price competition. Yet diffusion remained relatively slow, as the sector failed to provide a machine that would give housewives what they wanted—a means of doing their laundry within the privacy of the family unit, without significant inputs of either effort or time.